#include <bits/stdc++.h>
using namespace std;
typedef unsigned long long ul;
typedef signed long long ll;

int main(void)
{
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed;
  int a, b, c, d, e, f;
  char buf;
  cin >> a >> buf >> b >> buf >> c >> d >> buf >> e >> buf >> f;
  ll fos = a*100*100 + b*100 + c;
  ll tgt = d*100*100 + e*100 + f;
  cout << (fos >= tgt ? "YES" : "NO") << endl;
  return 0;
}