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