#include <stdio.h>

int main(){
	
int n;
scanf ("%d",&n);

int a = n/100;
int b = (n%100)/10;
int c = (n%10);

if (a == 7){
	printf ("yes");
}
else if (b == 7){
	printf ("yes");
}
else if (c == 7){
	printf ("yes");
}
else {
	printf ("no");
}
	return 0;
}