diff --git a/du4/program.c b/du4/program.c
index 413428f..cf15ec7 100644
--- a/du4/program.c
+++ b/du4/program.c
@@ -21,7 +21,7 @@ int call( double A,  double B,  double C, char AC){
         return printf("ZLE\n");
     }
     if(AC=='/'){
-        if(A/B==C || A/B==cC)return printf("OK\n");
+        if(A/B!=C || A/B!=cC)return printf("OK\n");
         return printf("ZLE\n");
     }
     return printf("CHYBA\n");