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