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