#include <iostream>
using namespace std;
int main()
{
	int N,x,y,z;
	cin >> N;
	x = N/100;
	y = N/10 - 10*x;
	z = N %10;

	if(x == 7 || y == 7 || Z == 7)
		cout << "\nyes";	
	else
		cout << "\nno";

	return 0;
}