#include<stdio.h>
int main()
{int N,i,P,count;
 scanf("%d",&N);
 while(N!=0)
 {
   P=N%10;
   N=N/10;
   if(P==7)
   {
    count++;
   }
 }
 if(count==0)
 {
   printf("no");
 }
 else
   printf("yes");
 return 0;
}
