#include <stdio.h>

int main(void)
{
  	int N=0;
  	int N1=0,N2=0,N3=0;
  
  	scanf("%d",&N);
  	N1=N/100;
  	
  	while(N<100){
    N2=N-100;
    N=N2;
    }
  	N2=N/10;
  
  	while(N<10){
    N3=N-10;
    N=N3;
    }
  	N3=N;
  
  	if(N1==7){
    puts("yes");
    }else if(N2=7){
    puts("yes");
    }else if(N3=7){
    puts("yea");
    }else{
    puts("no");
    }
  
  	return 0;
  
}
