diff --git a/a1/program.c b/a1/program.c
index 81897c8..b989322 100644
--- a/a1/program.c
+++ b/a1/program.c
@@ -30,7 +30,7 @@ int main(){
         int d1,d2,d3;
                 int res=sscanf(start,"%d %d %d",&d1,&d2,&d3);
 
-        if(res!=3){
+        if(res!=3||d1==0||d2==0||d3==0){
                         printf("Neplatny datum.\n");
                         while((*start)!='\n')start++;
                         start++;