#include <stdio.h>

int main(){
	int n[3];
	for (int i = 0; i < 3; i++) {
		scanf("%d", &n[i]);//_s
	}
	if (n[0] == 7) {
		printf("yes");
	}
	
	if (n[1] == 7) {
		printf("yes");
	}
	if (n[2] == 7) {
		printf("yes");
	}
	else {
		printf("no");
	}
		
	return 0;
}