diff --git a/subjects/blood_types_s/main.rs b/subjects/blood_types_s/main.rs
new file mode 100644
index 00000000..60fd9be3
--- /dev/null
+++ b/subjects/blood_types_s/main.rs
@@ -0,0 +1,19 @@
+use blood_types_s::{Antigen, BloodType, RhFactor};
+
+fn main() {
+    let blood_type = BloodType {
+        antigen: Antigen::O,
+        rh_factor: RhFactor::Positive,
+    };
+    println!("recipients of O+ {:?}", blood_type.recipients());
+    println!("donors of O+ {:?}", blood_type.donors());
+    let another_blood_type = BloodType {
+        antigen: Antigen::O,
+        rh_factor: RhFactor::Positive,
+    };
+    println!(
+        "donors of O+ can receive from {:?} {:?}",
+        &another_blood_type,
+        blood_type.can_receive_from(&another_blood_type)
+    );
+}
diff --git a/subjects/car_rental/main.rs b/subjects/car_rental/main.rs
new file mode 100644
index 00000000..7c8923da
--- /dev/null
+++ b/subjects/car_rental/main.rs
@@ -0,0 +1,31 @@
+use car_rental::*;
+use std::cell::RefCell;
+
+fn main() {
+    let car_rental = RentalBusiness {
+        car: RefCell::new(Car {
+            color: "red".to_string(),
+            plate: "AAA".to_string(),
+        }),
+    };
+
+    println!("{:?}", car_rental.rent_car());
+    println!("{:?}", car_rental.repair_car());
+
+    {
+        let mut car = car_rental.repair_car();
+        car.color = "blue".to_string();
+    }
+
+    println!("{:?}", car_rental.rent_car());
+
+    car_rental.change_car(Car {
+        color: "pink".to_string(),
+        plate: "WWW".to_string(),
+    });
+
+    println!("{:?}", car_rental.rent_car());
+
+    println!("{:?}", car_rental.sell_car());
+    println!("{:?}", car_rental.sell_car());
+}
diff --git a/subjects/check_user_name/main.rs b/subjects/check_user_name/main.rs
new file mode 100644
index 00000000..a6204cd9
--- /dev/null
+++ b/subjects/check_user_name/main.rs
@@ -0,0 +1,12 @@
+use check_user_name::*;
+
+fn main() {
+    let user0 = User::new("Didier".to_string(), AccessLevel::Admin);
+    println!("{:?}", check_user_name(&user0));
+
+    let user1 = User::new("Mary".to_string(), AccessLevel::Normal);
+    println!("{:?}", check_user_name(&user1));
+
+    let user2 = User::new("John".to_string(), AccessLevel::Guest);
+    println!("{:?}", check_user_name(&user2));
+}
diff --git a/subjects/count_factorial_steps/main.rs b/subjects/count_factorial_steps/main.rs
new file mode 100644
index 00000000..32d18fcd
--- /dev/null
+++ b/subjects/count_factorial_steps/main.rs
@@ -0,0 +1,10 @@
+use count_factorial_steps::count_factorial_steps;
+
+fn main() {
+    println!(
+        "The factorial steps of 720 = {}",
+        count_factorial_steps(720)
+    );
+    println!("The factorial steps of 13 = {}", count_factorial_steps(13));
+    println!("The factorial steps of 6 = {}", count_factorial_steps(6));
+}
diff --git a/subjects/counting_words/main.rs b/subjects/counting_words/main.rs
new file mode 100644
index 00000000..eced2a4c
--- /dev/null
+++ b/subjects/counting_words/main.rs
@@ -0,0 +1,9 @@
+use counting_words::counting_words;
+use std::collections::HashMap;
+
+fn main() {
+    println!("{:?}", counting_words("Hello, world!"));
+    println!("{:?}", counting_words("“Two things are infinite: the universe and human stupidity; and I'm not sure about the universe.”
+    ― Albert Einstein "));
+    println!("{:?}", counting_words("Batman, BATMAN, batman, Stop stop"));
+}
diff --git a/subjects/display_table/main.rs b/subjects/display_table/main.rs
new file mode 100644
index 00000000..72389813
--- /dev/null
+++ b/subjects/display_table/main.rs
@@ -0,0 +1,29 @@
+fn main() {
+    let mut table = Table::new();
+    println!("{}", table);
+    table.headers = vec![
+        String::from("Model"),
+        String::from("Piece N°"),
+        String::from("In Stock"),
+        String::from("Description"),
+    ];
+    table.add_row(&[
+        String::from("model 1"),
+        String::from("43-EWQE304"),
+        String::from("30"),
+        String::from("Piece for x"),
+    ]);
+    table.add_row(&[
+        String::from("model 2"),
+        String::from("98-QCVX5433"),
+        String::from("100000000"),
+        String::from("-"),
+    ]);
+    table.add_row(&[
+        String::from("model y"),
+        String::from("78-NMNH"),
+        String::from("60"),
+        String::from("nothing"),
+    ]);
+    println!("{}", table);
+}
diff --git a/subjects/dress_code/main.rs b/subjects/dress_code/main.rs
new file mode 100644
index 00000000..2e4d1b21
--- /dev/null
+++ b/subjects/dress_code/main.rs
@@ -0,0 +1,6 @@
+use negative_spelling::*;
+
+fn main() {
+    println!("{}", negative_spell(-1234));
+    println!("{}", negative_spell(100));
+}
diff --git a/subjects/drop_the_blog/main.rs b/subjects/drop_the_blog/main.rs
new file mode 100644
index 00000000..837cfb9f
--- /dev/null
+++ b/subjects/drop_the_blog/main.rs
@@ -0,0 +1,31 @@
+use drop_the_blog::*;
+use std::rc::Rc;
+
+fn main() {
+    let blog = Blog::new();
+    let (id, article) = blog.new_article(String::from("Winter is coming"));
+    let (id1, article1) = blog.new_article(String::from("The story of the universe"));
+
+    article.discard();
+
+    println!("{:?}", (blog.is_dropped(id), id, &blog.drops));
+
+    article1.discard();
+    println!("{:?}", (blog.is_dropped(id1), id1, &blog.drops));
+
+    let (id2, article2) = blog.new_article(String::from("How to cook 101"));
+    let article2 = Rc::new(article2);
+    let article2_clone = article2.clone();
+
+    drop(article2_clone);
+
+    println!(
+        "{:?}",
+        (
+            blog.is_dropped(id2),
+            id2,
+            &blog.drops,
+            Rc::strong_count(&article2)
+        )
+    );
+}
diff --git a/subjects/filter_table/main.rs b/subjects/filter_table/main.rs
new file mode 100644
index 00000000..060f0bee
--- /dev/null
+++ b/subjects/filter_table/main.rs
@@ -0,0 +1,28 @@
+fn main() {
+    let mut table = Table::new();
+    table.headers = vec![
+        "Name".to_string(),
+        "Last Name".to_string(),
+        "ID Number".to_string(),
+    ];
+    table.add_row(&[
+        "Adam".to_string(),
+        "Philips".to_string(),
+        "123456789".to_string(),
+    ]);
+    table.add_row(&[
+        "Adamaris".to_string(),
+        "Shelby".to_string(),
+        "1111123456789".to_string(),
+    ]);
+    table.add_row(&[
+        "Ackerley".to_string(),
+        "Philips".to_string(),
+        "123456789".to_string(),
+    ]);
+    let filter_names = |col: &str| col == "Name";
+    println!("{:?}", table.filter_col(filter_names));
+
+    let filter_philips = |lastname: &str| lastname == "Philips";
+    println!("{:?}", table.filter_row("Last Name", filter_philips));
+}
diff --git a/subjects/flat_tree/main.rs b/subjects/flat_tree/main.rs
new file mode 100644
index 00000000..abf25c3f
--- /dev/null
+++ b/subjects/flat_tree/main.rs
@@ -0,0 +1,15 @@
+fn main() {
+    let mut tree = BTreeSet::new();
+    tree.insert(34);
+    tree.insert(0);
+    tree.insert(9);
+    tree.insert(30);
+    println!("{:?}", flatten_tree(&tree));
+
+    let mut tree = BTreeSet::new();
+    tree.insert("Slow");
+    tree.insert("kill");
+    tree.insert("will");
+    tree.insert("Horses");
+    println!("{:?}", flatten_tree(&tree));
+}
diff --git a/subjects/format_me/main.rs b/subjects/format_me/main.rs
new file mode 100644
index 00000000..4890d7e5
--- /dev/null
+++ b/subjects/format_me/main.rs
@@ -0,0 +1,24 @@
+use format_me::*;
+
+fn main() {
+    println!(
+        "{}",
+        Park {
+            name: "Les Tuileries".to_string(),
+            park_type: ParkType::Garden,
+            address: "Pl. de la Concorde".to_string(),
+            cap: "75001".to_string(),
+            state: "France".to_string()
+        }
+    );
+    println!(
+        "{}",
+        Park {
+            name: "".to_string(),
+            park_type: ParkType::Playground,
+            address: "".to_string(),
+            cap: "".to_string(),
+            state: "".to_string()
+        }
+    );
+}
diff --git a/subjects/get_document_id/README.md b/subjects/get_document_id/README.md
index 77d63f1f..5484dc55 100644
--- a/subjects/get_document_id/README.md
+++ b/subjects/get_document_id/README.md
@@ -86,6 +86,7 @@ fn main() {
         Err(err) => println!("Error: {:?}", err),
     };
 }
+
 ```
 
 And its output:
diff --git a/subjects/get_document_id/main.rs b/subjects/get_document_id/main.rs
new file mode 100644
index 00000000..689833ad
--- /dev/null
+++ b/subjects/get_document_id/main.rs
@@ -0,0 +1,29 @@
+use get_document_id::*;
+
+fn main() {
+    let office_ok = OfficeOne {
+        next_office: Ok(OfficeTwo {
+            next_office: Ok(OfficeThree {
+                next_office: Ok(OfficeFour {
+                    document_id: Ok(13),
+                }),
+            }),
+        }),
+    };
+    let office_closed = {
+        OfficeOne {
+            next_office: Ok(OfficeTwo {
+                next_office: Err(ErrorOffice::OfficeClose(23)),
+            }),
+        }
+    };
+
+    match office_ok.get_document_id() {
+        Ok(id) => println!("Found a document with id {}", id),
+        Err(err) => println!("Error: {:?}", err),
+    };
+    match office_closed.get_document_id() {
+        Ok(id) => println!("Found a document with id {}", id),
+        Err(err) => println!("Error: {:?}", err),
+    };
+}
diff --git a/subjects/insertion_sort/main.rs b/subjects/insertion_sort/main.rs
new file mode 100644
index 00000000..7845b7dd
--- /dev/null
+++ b/subjects/insertion_sort/main.rs
@@ -0,0 +1,13 @@
+fn main() {
+    let mut target = [5, 3, 7, 2, 1, 6, 8, 4];
+    // executes the first iteration of the algorithm
+    insertion_sort(&mut target, 1);
+    println!("{:?}", target);
+
+    let mut target = [5, 3, 7, 2, 1, 6, 8, 4];
+    let len = target.len();
+    // executes len - 1 iterations of the algorithm
+    // i.e. sorts the slice
+    insertion_sort(&mut target, len - 1);
+    println!("{:?}", target);
+}
diff --git a/subjects/inv_pyramid/main.rs b/subjects/inv_pyramid/main.rs
new file mode 100644
index 00000000..d8b2df66
--- /dev/null
+++ b/subjects/inv_pyramid/main.rs
@@ -0,0 +1,19 @@
+fn main() {
+    let a = inv_pyramid(String::from("#"), 1);
+    let b = inv_pyramid(String::from("a"), 2);
+    let c = inv_pyramid(String::from(">"), 5);
+    let d = inv_pyramid(String::from("&"), 8);
+
+    for v in a.iter() {
+        println!("{:?}", v);
+    }
+    for v in b.iter() {
+        println!("{:?}", v);
+    }
+    for v in c.iter() {
+        println!("{:?}", v);
+    }
+    for v in d.iter() {
+        println!("{:?}", v);
+    }
+}
diff --git a/subjects/lucas_number/main.rs b/subjects/lucas_number/main.rs
new file mode 100644
index 00000000..ecc5c0ff
--- /dev/null
+++ b/subjects/lucas_number/main.rs
@@ -0,0 +1,24 @@
+use lucas_number::lucas_number;
+
+fn main() {
+    println!(
+        "The element in the position {} in Lucas Numbres is {}",
+        2,
+        lucas_number(2)
+    );
+    println!(
+        "The element in the position {} in Lucas Numbres is {}",
+        5,
+        lucas_number(5)
+    );
+    println!(
+        "The element in the position {} in Lucas Numbres is {}",
+        10,
+        lucas_number(10)
+    );
+    println!(
+        "The element in the position {} in Lucas Numbres is {}",
+        13,
+        lucas_number(13)
+    );
+}
diff --git a/subjects/lunch_queue/main.rs b/subjects/lunch_queue/main.rs
new file mode 100644
index 00000000..f28bb371
--- /dev/null
+++ b/subjects/lunch_queue/main.rs
@@ -0,0 +1,17 @@
+fn main() {
+    let mut list = Queue::new();
+    list.add(String::from("Marie"), 20);
+    list.add(String::from("Monica"), 15);
+    list.add(String::from("Ana"), 5);
+    list.add(String::from("Alice"), 35);
+    println!("{:?}", list);
+
+    println!("{:?}", list.search("Marie"));
+    println!("{:?}", list.search("Alice"));
+    println!("{:?}", list.search("someone"));
+
+    println!("removed {:?}", list.rm());
+    println!("list {:?}", list);
+    list.invert_queue();
+    println!("invert {:?}", list);
+}
diff --git a/subjects/matrix_determinant/main.rs b/subjects/matrix_determinant/main.rs
new file mode 100644
index 00000000..30ecbdab
--- /dev/null
+++ b/subjects/matrix_determinant/main.rs
@@ -0,0 +1,8 @@
+fn main() {
+    let matrix = [[1, 2, 4], [2, -1, 3], [4, 0, 1]];
+
+    println!(
+        "The determinant of the matrix:\n|1  2  4|\n|2 -1  3|  = {}\n|4  0  1|",
+        matrix_determinant(matr)
+    );
+}
diff --git a/subjects/matrix_display/main.rs b/subjects/matrix_display/main.rs
new file mode 100644
index 00000000..34c270e1
--- /dev/null
+++ b/subjects/matrix_display/main.rs
@@ -0,0 +1,4 @@
+fn main() {
+    let matrix = Matrix::new(&[&[1, 2, 3], &[4, 5, 6], &[7, 8, 9]]);
+    println!("{}", matrix);
+}
diff --git a/subjects/matrix_multiplication/main.rs b/subjects/matrix_multiplication/main.rs
new file mode 100644
index 00000000..373500e8
--- /dev/null
+++ b/subjects/matrix_multiplication/main.rs
@@ -0,0 +1,7 @@
+use matrix_multiplication::*;
+
+fn main() {
+    let matrix = Matrix((1, 3), (4, 5));
+    println!("Original matrix {:?}", matrix);
+    println!("Matrix after multiply {:?}", multiply(matrix, 3));
+}
diff --git a/subjects/min_and_max/main.rs b/subjects/min_and_max/main.rs
new file mode 100644
index 00000000..294870c1
--- /dev/null
+++ b/subjects/min_and_max/main.rs
@@ -0,0 +1,5 @@
+use min_and_max::min_and_max;
+
+fn main() {
+    println!("Minimum and maximum are: {:?}", min_and_max(9, 2, 4));
+}
diff --git a/subjects/modify_letter/main.rs b/subjects/modify_letter/main.rs
new file mode 100644
index 00000000..0a3f3172
--- /dev/null
+++ b/subjects/modify_letter/main.rs
@@ -0,0 +1,7 @@
+use modify_letter::*modify_letter*;
+
+fn main() {
+    println!("{}", remove_letter_sensitive("Jojhn jis sljeepjjing", 'j'));
+    println!("{}", remove_letter_insensitive("JaimA ais swiaAmmingA", 'A'));
+    println!("{}", swap_letter_case("byE bye", 'e'));
+}
diff --git a/subjects/moving_targets/main.rs b/subjects/moving_targets/main.rs
new file mode 100644
index 00000000..4565bb73
--- /dev/null
+++ b/subjects/moving_targets/main.rs
@@ -0,0 +1,14 @@
+use moving_targets::*;
+
+fn main() {
+    let mut field = Field::new();
+
+    println!("{:?}", field.pop());
+    field.push(Target { size: 12, xp: 2 });
+    println!("{:?}", *field.peek().unwrap());
+    field.push(Target { size: 24, xp: 4 });
+    println!("{:?}", field.pop());
+    let last_target = field.peek_mut().unwrap();
+    *last_target = Target { size: 2, xp: 0 };
+    println!("{:?}", field.pop());
+}
diff --git a/subjects/nextprime/main.rs b/subjects/nextprime/main.rs
new file mode 100644
index 00000000..2354ee4a
--- /dev/null
+++ b/subjects/nextprime/main.rs
@@ -0,0 +1,4 @@
+fn main() {
+    println!("The next prime after 4 is: {}", next_prime(4));
+    println!("The next prime after 11 is: {}", next_prime(11));
+}
diff --git a/subjects/office_worker/main.rs b/subjects/office_worker/main.rs
new file mode 100644
index 00000000..99f4e206
--- /dev/null
+++ b/subjects/office_worker/main.rs
@@ -0,0 +1,9 @@
+use office_worker::*;
+
+fn main() {
+    println!("New worker: {:?}", OfficeWorker::from("Manuel,23,admin"));
+    println!(
+        "New worker: {:?}",
+        OfficeWorker::from("Jean Jacques,44,guest")
+    );
+}
diff --git a/subjects/order_books/main.rs b/subjects/order_books/main.rs
new file mode 100644
index 00000000..bb5a02f8
--- /dev/null
+++ b/subjects/order_books/main.rs
@@ -0,0 +1,39 @@
+pub use library::books::Book;
+pub use library::writers::Writer;
+
+fn main() {
+    let mut writer_a = Writer {
+        first_name: "William".to_string(),
+        last_name: "Shakespeare".to_string(),
+        books: vec![
+            Book {
+                title: "Hamlet".to_string(),
+                year: 1600,
+            },
+            Book {
+                title: "Othelo".to_string(),
+                year: 1603,
+            },
+            Book {
+                title: "Romeo and Juliet".to_string(),
+                year: 1593,
+            },
+            Book {
+                title: "MacBeth".to_string(),
+                year: 1605,
+            },
+        ],
+    };
+
+    println!("Before ordering");
+    for b in &writer_a.books {
+        println!("{:?}", b.title);
+    }
+
+    order_books(&mut writer_a);
+
+    println!("\nAfter ordering");
+    for b in writer_a.books {
+        println!("{:?}", b.title);
+    }
+}
diff --git a/subjects/organize_garage/main.rs b/subjects/organize_garage/main.rs
new file mode 100644
index 00000000..aa4d86e8
--- /dev/null
+++ b/subjects/organize_garage/main.rs
@@ -0,0 +1,14 @@
+use organize_garage::*;
+
+fn main() {
+    let mut garage = Garage {
+        left: Some(5),
+        right: Some(2),
+    };
+
+    println!("{:?}", garage);
+    garage.move_to_right();
+    println!("{:?}", garage);
+    garage.move_to_left();
+    println!("{:?}", garage);
+}
diff --git a/subjects/own_and_return/README.md b/subjects/own_and_return/README.md
index 86ee4d8c..14517c56 100644
--- a/subjects/own_and_return/README.md
+++ b/subjects/own_and_return/README.md
@@ -22,7 +22,6 @@ pub fn read_film_name(/* to be implemented */) -> String {
 pub fn take_film_name(/* to be implemented */) -> String {
 }
 
-
 ```
 
 ### Usage
@@ -32,7 +31,6 @@ Here is a possible program to test your function:
 ```rust
 use own_and_return::*;
 
-
 pub struct Film {
     pub name: String,
 }
@@ -47,6 +45,7 @@ fn main() {
     // you can test this function by commenting out the first print statement,
     // you should see the expected output without errors in this case
 }
+
 ```
 
 And its output:
diff --git a/subjects/own_and_return/main.rs b/subjects/own_and_return/main.rs
new file mode 100644
index 00000000..96e8a7d3
--- /dev/null
+++ b/subjects/own_and_return/main.rs
@@ -0,0 +1,18 @@
+use own_and_return::*;
+
+pub struct Film {
+    pub name: String,
+}
+
+fn main() {
+    let my_film = Film {
+        name: "Terminator".toString(),
+    };
+    println!("{}", take_film_name(/* to be implemented */));
+    // the order of the print statements is intentional, if your implementation is correct,
+    // you should have a compile error because my_film was consumed
+    println!("{}", read_film_name(/* to be implemented */));
+    println!("{}", take_film_name(/*to be implemented*/))
+    // you can test this function by commenting out the first print statement,
+    // you should see the expected output without errors in this case
+}
diff --git a/subjects/partial_sums/main.rs b/subjects/partial_sums/main.rs
new file mode 100644
index 00000000..eb2cd31e
--- /dev/null
+++ b/subjects/partial_sums/main.rs
@@ -0,0 +1,6 @@
+fn main() {
+    println!(
+        "Partial sums of [5, 18, 3, 23] is : {:?}",
+        parts_sums(&[5, 18, 3, 23])
+    );
+}
diff --git a/subjects/previousprime/main.rs b/subjects/previousprime/main.rs
new file mode 100644
index 00000000..b0766729
--- /dev/null
+++ b/subjects/previousprime/main.rs
@@ -0,0 +1,3 @@
+fn main() {
+    println!("The previous prime number before 34 is: {}", prev_prime(34));
+}
diff --git a/subjects/prime_checker/main.rs b/subjects/prime_checker/main.rs
new file mode 100644
index 00000000..bb8bfe4c
--- /dev/null
+++ b/subjects/prime_checker/main.rs
@@ -0,0 +1,7 @@
+use prime_checker::*;
+
+fn main() {
+    println!("Is {} prime? {:?}", 2, prime_checker(2));
+    println!("Is {} prime? {:?}", 14, prime_checker(14));
+    println!("Is {} prime? {:?}", 2147483647, prime_checker(2147483647));
+}
diff --git a/subjects/profanity_filter/main.rs b/subjects/profanity_filter/main.rs
new file mode 100644
index 00000000..02607b9a
--- /dev/null
+++ b/subjects/profanity_filter/main.rs
@@ -0,0 +1,15 @@
+use profanity_filter::*;
+
+fn main() {
+    let m0 = Message::new("hello there".to_string(), "toby".to_string());
+    println!("{:?}", check_ms(&m0));
+
+    let m1 = Message::new("".to_string(), "toby".to_string());
+    println!("{:?}", check_ms(&m1));
+
+    let m2 = Message::new("you are stupid".to_string(), "toby".to_string());
+    println!("{:?}", check_ms(&m2));
+
+    let m3 = Message::new("stupid".to_string(), "toby".to_string());
+    println!("{:?}", check_ms(&m3));
+}
diff --git a/subjects/queens/main.rs b/subjects/queens/main.rs
new file mode 100644
index 00000000..f07f24e1
--- /dev/null
+++ b/subjects/queens/main.rs
@@ -0,0 +1,17 @@
+fn main() {
+    let white_queen = Queen::new(ChessPosition::new(2, 2).unwrap());
+    let black_queen = Queen::new(ChessPosition::new(0, 4).unwrap());
+
+    println!(
+        "Is it possible for the queens to attack each other? => {}",
+        white_queen.can_attack(&black_queen)
+    );
+
+    let white_queen = Queen::new(ChessPosition::new(1, 2).unwrap());
+    let black_queen = Queen::new(ChessPosition::new(0, 4).unwrap());
+
+    println!(
+        "Is it possible for the queens to attack each other? => {}",
+        white_queen.can_attack(&black_queen)
+    );
+}
diff --git a/subjects/reverse_it/main.rs b/subjects/reverse_it/main.rs
new file mode 100644
index 00000000..f5464a8c
--- /dev/null
+++ b/subjects/reverse_it/main.rs
@@ -0,0 +1,4 @@
+fn main() {
+    println!("{}", reverse_it(123));
+    println!("{}", reverse_it(-123));
+}
diff --git a/subjects/rot21/main.rs b/subjects/rot21/main.rs
new file mode 100644
index 00000000..fc32129a
--- /dev/null
+++ b/subjects/rot21/main.rs
@@ -0,0 +1,9 @@
+use rot21::rot21;
+
+fn main() {
+    println!("The letter \"a\" becomes: {}", rot21("a"));
+    println!("The letter \"m\" becomes: {}", rot21("m"));
+    println!("The word \"MISS\" becomes: {}", rot21("MISS"));
+    println!("Your cypher wil be: {}", rot21("Testing numbers 1 2 3"));
+    println!("Your cypher wil be: {}", rot21("rot21 works!"));
+}
diff --git a/subjects/scytale_decoder/main.rs b/subjects/scytale_decoder/main.rs
new file mode 100644
index 00000000..79630144
--- /dev/null
+++ b/subjects/scytale_decoder/main.rs
@@ -0,0 +1,11 @@
+fn main() {
+    println!(
+        "\"sec yCtoadle\" size=2 -> {:?}",
+        scytale_decoder("sec yCtoadle".to_string(), 2)
+    );
+
+    println!(
+        "\"steoca dylCe\" size=4 -> {:?}",
+        scytale_decoder("steoca dylCe".to_string(), 4)
+    );
+}
diff --git a/subjects/smallest/main.rs b/subjects/smallest/main.rs
new file mode 100644
index 00000000..1f2f166d
--- /dev/null
+++ b/subjects/smallest/main.rs
@@ -0,0 +1,15 @@
+use smallest::smallest;
+use std::collections::HashMap;
+
+fn main() {
+    let mut hash = HashMap::new();
+    hash.insert("Cat", 122);
+    hash.insert("Dog", 333);
+    hash.insert("Elephant", 334);
+    hash.insert("Gorilla", 14);
+
+    println!(
+        "The smallest of the elements in the HashMap is {}",
+        smallest(hash)
+    );
+}