diff --git a/main.py b/main.py
index 7cdde79..c1d0cbb 100644
--- a/main.py
+++ b/main.py
@@ -5,7 +5,7 @@ def get_memory(variable_name: str) -> list[bool]:
     while True:
         input_chars: list[str] = list(input(f"Enter {variable_name}: "))
 
-        if all(character.isnumeric() and (character == "1" or character == "0") for character in input_chars):
+        if all(character in ["0", "1"] for character in input_chars):
             return [True if character == "1" else False for character in input_chars]
         else:
             print(f"[ERROR] The {variable_name} may contain only 1-s and 0-s!")
@@ -16,8 +16,8 @@ if __name__ == '__main__':
 
     print(reg)
 
-    print(reg.left_shift(3))
+    print(reg.left_shift())
     print(reg)
 
-    print(reg.right_shift(3))
+    print(reg.right_shift())
     print(reg)