diff --git a/du2/program.c b/du2/program.c
index c8c7ef4..819886d 100644
--- a/du2/program.c
+++ b/du2/program.c
@@ -14,7 +14,7 @@ int main(){
     int idx=0;
     while (1){
         int r=scanf("%d",&value);
-        if(r!=1||idx==VELKOST_POLA){
+        if(r!=1||idx==VELKOST_POLA||pole[idx]<0){
             break;
         }
         pole[idx]=value;