#include <bits/stdc++.h>
using namespace std;
inline int read() {
  int f = 1, ans = 0;
  char c;
  while (c < '0' || c > '9') {
    if (c == '-') f = -1;
    c = getchar();
  }
  while (c >= '0' && c <= '9') {
    ans = ans * 10 + c - '0';
    c = getchar();
  }
  return ans * f;
}
int x, y, z, a, b, c, ans;
int main() {
  x = read(), y = read(), z = read(), a = read(), b = read(), c = read();
  ans = a + b + c;
  if (a < x) {
    printf("NO");
    return 0;
  }
  ans -= x;
  a -= x;
  if (a + b < y) {
    printf("NO");
    return 0;
  }
  ans -= y;
  if (ans < z) {
    printf("NO");
    return 0;
  } else {
    printf("YES");
    return 0;
  }
}
