#include <bits/stdc++.h>
using namespace std;
void input() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
}
int main(int argc, char const *argv[]) {
  input();
  int x, y, z, a, b, c;
  cin >> x >> y >> z;
  cin >> a >> b >> c;
  int f = 1;
  if (a >= x) {
    a -= x;
  } else
    f = 0;
  if (a + b >= y) {
    b -= y;
  } else
    f = 0;
  if (a + b + c < z) {
    f = 0;
  }
  if (f) {
    cout << "YES";
  } else
    cout << "NO";
  return 0;
}
