diff --git a/du4/program.c b/du4/program.c
index 0529559..cbfc483 100644
--- a/du4/program.c
+++ b/du4/program.c
@@ -42,6 +42,7 @@ if(ac=='+')add(a,b,c,ac);
 if(ac=='-')subtr(a,b,c,ac);
 if(ac=='*')multi(a,b,c,ac);
 if(ac=='/')divi(a,b,c,ac);
+printf("CHYBA\n");
     return 0;
 }