#include<stdio.h>

int main(){
  int n;
  int ichi,ju,hyaku;
  
  scanf("%d",&n);
  hyaku = n/100;
  ichi = n%10;
  ju = n - (hyaku*100) - ichi;
  if(ichi==7||ju==7||hyaku==7)
    printf("yes");
  else
    printf("no");
  return 0;
}