fix problem with + and -

validity_check.py

@@ -22,8 +22,8 @@ if __name__ == "__main__":
         exit(1)
 
     prev_line = modifs[1].split(',')
-    modifs[0][0]=' '
-    modifs[0][1]=' '
+    modifs[0]= modifs[0][1:]
+    modifs[1]=modifs[1][1:]
     
     for i in range(modifs[0]):
         if i<3 and prev_line[i] != curr_line[i] :