#include <bits/stdc++.h>
using namespace std;
int main() {
  int n[3], g[3];
  for (int i = 0; i < 3; i++) {
    cin >> n[i];
  }
  for (int i = 0; i < 3; i++) {
    cin >> g[i];
  }
  if (n[0] > g[0]) {
    cout << "NO" << endl;
    return 0;
  }
  if (g[1] + g[0] - n[0] < n[1]) {
    cout << "NO" << endl;
    return 0;
  }
  if (g[0] + g[1] + g[2] - n[0] - n[1] < n[2]) {
    cout << "NO" << endl;
    return 0;
  }
  cout << "YES" << endl;
  return 0;
}
