diff --git a/du3/program.c b/du3/program.c
index 109ff88..f31c787 100644
--- a/du3/program.c
+++ b/du3/program.c
@@ -27,7 +27,7 @@ int main() {
 
         char operacia = *cast2; //nacitam si do jednotkovej premennej char prvy prvok pola cast2, 
                                 //ktory by malo byt znamienko operacie
-        if (operacia != '+' || operacia != '-' || operacia != '*' || operacia != '/') {
+        if (operacia != '+' && operacia != '-' && operacia != '*' && operacia != '/') {
             printf ("CHYBA\n");
             continue;
         }