#include <bits/stdc++.h>
using namespace std;
int main() {
  long long a, b, c;
  cin >> a >> b >> c;
  long long d, e, f;
  cin >> d >> e >> f;
  long long ff = 0;
  long long cc = d + e;
  if (d >= a) {
    d -= a;
    cc = d + e;
  } else
    ff = 1;
  if (d + e >= b) {
    cc -= b;
  } else
    ff = 1;
  if (cc + f < c) ff = 1;
  if (ff)
    cout << "NO";
  else
    cout << "YES";
  return 0;
}
