#include <sstream>
#include <string>
#include <vector>
#include <map>
#include <algorithm>
#include <iostream>
#include <utility>
#include <set>
#include <cctype>
#include <queue>
#include <stack>
#include <cstdio>
#include <cstdlib>
#include <cmath>

#define INF 1000000000

using namespace std;
typedef long long ll;

int main(void) {
    int s1[3], s2[3];
    scanf("%d.%d.%d", s1, s1+1, s1+2);
    scanf("%d.%d.%d", s2, s2+1, s2+2);
    for (int i = 0; i < 3; i++) {
        if (s1[i] > s2[i]) {
            cout << "YES" << endl;
            return 0;
        } else if (s1[i] < s2[i]) {
            break;
        } else if (i == 2) {
            cout << "YES" << endl;
            return 0;
        }
    }
    cout << "NO" << endl;
    return 0;
}