#include <bits/stdc++.h>
using namespace std;
const long double eps = 1e-13;
const long double PI = acos(-1);
const int INF = (int)1e9;
const long long INFF = (long long)1e17;
const int mod = 998244353;
const int MXN = (int)1e6 + 7;
int main() {
  int x, y, z;
  cin >> x >> y >> z;
  int a, b, c;
  cin >> a >> b >> c;
  bool gg = 0;
  if (x > a) gg = 1;
  a -= x;
  if (y > a + b) gg = 1;
  if (a + b + c < y + z) gg = 1;
  puts(gg ? "NO" : "YES");
  return 0;
}
