diff --git a/level3/source.c b/level3/source.c
index 842087c..b6dabfb 100644
--- a/level3/source.c
+++ b/level3/source.c
@@ -1,6 +1,8 @@
 #include <stdio.h>
 #include <stdlib.h>
 
+int m;
+
 void v(void)
 {
 	char buf[520];