#include <iostream>
using namespace std;
int main(){
    int a[3],b[3];char z;
    cin>>a[0]>>z>>a[1]>>z>>a[2];
    cin>>b[0]>>z>>b[1]>>z>>b[2];
    for(int i = 0; 3 > i; i++){
        if(a[i] < b[i]){
            cout << "NO" << endl;
            return 0;
        }else if(a[i] > b[i]){
            cout << "YES" << endl;
            return 0;
        }
    }
    cout << "YES" << endl;
}