docs(canyoucount): fix subject

subjects/canyoucount/README.md

@@ -2,17 +2,17 @@
 
 ### Instructions
 
-Your program will receive some arguments. Count how many characters they have in total and print them. If the number of arguments is not enough, print 0.
+Your program will receive some arguments. Count how many characters they have in total and print them. 
+
+- If the number of arguments is invalid it should print `0`.
 
 ### Usage
 
 ```console
 $ go run . "hello" "how are you?" | cat -e
 17$
-$ go run . "a" | cat -e
+$ go run . "hi" | cat -e
-1$
+2$
-$ go run . "I am" "myself." | cat -e
-11$
 $ go run . | cat -e
 0$
 ```