#include <bits/stdc++.h>
using namespace std;
int t;
int n, m, k;
int h[105];
int main() {
  scanf("%d", &t);
  while (t--) {
    scanf("%d%d%d", &n, &m, &k);
    for (int i = 0; i < n; ++i) {
      scanf("%d", &h[i]);
    }
    int bag = m;
    int solve = 1;
    for (int i = 0; i < n - 1; ++i) {
      if (h[i] >= h[i + 1] - k) {
        bag += h[i] - max(h[i + 1] - k, 0);
      } else {
        bag -= (h[i + 1] - k) - h[i];
      }
      if (bag < 0) {
        solve = 0;
        break;
      }
    }
    if (solve) {
      puts("YES");
    } else {
      puts("NO");
    }
  }
  return (0);
}
