#include<stdio.h>

int main(){
  int n;
  int truss_a,truss_b,truss_c;
  int kazu_a,kazu_b;
  scanf("%d",&n);
  truss_a = n/100;
  kazu_a = n%100;
  truss_b = kazu_a/10;
  kazu_b = kazu_a%10;
  truss_c= kazu_b;
  if(truss_a==7||truss_b==7||truss_c==7)
    printf("yes");
  else
    printf("no");
  return 0;
}