#include <bits/stdc++.h>
using namespace std;
int main() {
  int x, y, z, a, b, c;
  while (cin >> x >> y >> z >> a >> b >> c) {
    int p, q;
    p = (a - x) + b;
    if (x > a) {
      cout << "NO" << endl;
      continue;
    } else if (p < y) {
      cout << "NO" << endl;
      continue;
    } else if ((p - y) + c < z) {
      cout << "NO" << endl;
      continue;
    } else
      cout << "YES" << endl;
  }
  return 0;
}
