diff --git a/md5.cpp b/md5.hpp
similarity index 91%
rename from md5.cpp
rename to md5.hpp
index 5351476..e360d35 100644
--- a/md5.cpp
+++ b/md5.hpp
@@ -1,3 +1,5 @@
+#pragma once
+
 #include <iostream>
 #include <iomanip>
 #include <string>
@@ -123,16 +125,4 @@ public:
 
 		return result;
 	}
-};
-
-int main() {
-	MD5 md5;
-	
-	std::cout << md5.hash("") << std::endl;
-	std::cout << md5.hash("a") << std::endl;
-	std::cout << md5.hash("abc") << std::endl;
-	std::cout << md5.hash("message digest") << std::endl;
-	std::cout << md5.hash("abcdefghijklmnopqrstuvwxyz") << std::endl;
-	
-	return 0;
-}
\ No newline at end of file
+};
\ No newline at end of file