#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
typedef long long int ll;
 
int main(){
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
	int x,y,z,a,b; char c;
	cin >> x >> c >> y >> c >> z;
	a=10001*x+101*y+z;
	cin >> x >> c >> y >> c >> z;
	b=10001*x+101*y+z;
	if(a>=b){
		cout << "YES" << endl; 
	}
	else{
		cout << "NO" << endl;
	}
}