#include <stdio.h>
void main(void){
	int previousA = 0,previousB = 0,previousC = 0;
	scanf("%d.%d.%d",previousA,previousB,previousC);
	int newA = 0,newB = 0,newC = 0;
	scanf("%d.%d.%d",newA,newB,newC);
	if(previousA == newA){
		printf("YES");
	}else{
		printf("NO");
	}
}