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