diff --git a/cv3/program.c b/cv3/program.c
index 14095c4..fdc3c32 100644
--- a/cv3/program.c
+++ b/cv3/program.c
@@ -21,6 +21,10 @@ int main(){
             return 0;
         }
         if(vstup[0] == '-' || vstup[0] == '+' || vstup[0] == '*' || vstup[0] == '/'){
+            if(counter < 2){
+                printf("not enough operands\n");
+                return 0;
+            }
             if(vstup[0] == '-'){
                 mystack.values[counter-2] = mystack.values[counter-2] - mystack.values[counter-1];
                 mystack.values[counter-1] = 0;