#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, d, m;
  int g, p, b;
  cin >> a >> d >> m >> g >> p >> b;
  int diff = 0;
  diff = g - a;
  if (diff >= 0) {
    diff = diff + p;
    diff = diff - d;
    if (diff >= 0) {
      diff = diff + b;
      diff = diff - m;
      if (diff >= 0) {
        cout << "YES";
      } else
        cout << "NO";
    } else
      cout << "NO";
  } else
    cout << "NO";
}
