diff --git a/subjects/cleanstr.md b/subjects/cleanstr.md
deleted file mode 100644
index 0a332e58..00000000
--- a/subjects/cleanstr.md
+++ /dev/null
@@ -1,27 +0,0 @@
-# cleanstr
-## Instructions
-
-Write a program that takes a string, and displays this string with exactly one
-space between words, with no spaces or tabs either at the beginning or the end,
-followed by a \n.
-
-A "word" is defined as a part of a string delimited either by spaces/tabs, or
-by the start/end of the string.
-
-If the number of arguments is not 1, or if there are no words to display, the
-program displays \n.
-
-And its output :
-
-```console
-student@ubuntu:~/student/cleanstr$ go build
-student@ubuntu:~/student/cleanstr$ ./cleanstr "you see it's easy to display the same thing" | cat -e
-you see it's easy to display the same thing$
-student@ubuntu:~/student/cleanstr$ ./cleanstr " only    it's  harder   " 
-only it's harder$
-student@ubuntu:~/student/cleanstr$ ./cleanstr " how funny" "Did you   hear Mathilde ?"
-$
-student@ubuntu:~/student/cleanstr$ ./cleanstr "" | cat -e 
-$
-student@ubuntu:~/student/cleanstr$
-```