#include <bits/stdc++.h>
using namespace std;
int main() {
  int x, y, z, g, p, b, c = 1;
  cin >> x >> y >> z >> g >> p >> b;
  if (g < x)
    c = 0;
  else {
    g -= x;
    if (y > g + p)
      c = 0;
    else {
      g = g + p;
      g -= y;
      if (z > g + b) c = 0;
    }
  }
  if (c == 0)
    cout << "NO";
  else
    cout << "YES";
}
