#include <bits/stdc++.h>
#define fastIO (cin.tie(0), cout.tie(0), ios::sync_with_stdio(false))
#define precise(i) fixed << setprecision(i)
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
using namespace std;
int main() {
  fastIO;

  string f, c;
  cin >> f >> c;

  string fossil, cur;

  for (size_t i = 0; i < 5; i += 2) {
    fossil += f[i];
    cur += c[i];
  }

  if (fossil > cur)
    cout << "YES" << '\n';
  else
    cout << "NO" << '\n';

  return 0;
}