#include <bits/stdc++.h>
using namespace std;
int h[110];
void solve() {
  int i, n, m, k;
  cin >> n >> m >> k;
  for (i = 0; i < n; i++) {
    cin >> h[i];
  }
  for (i = 0; i < n - 1; i++) {
    if (h[i] + k >= h[i + 1]) {
      m += min(h[i], h[i] - (h[i + 1] - k));
    } else {
      m -= h[i + 1] - k - h[i];
      if (m < 0) {
        cout << "NO" << endl;
        return;
      }
    }
  }
  cout << "YES" << endl;
}
int main() {
  int t;
  cin >> t;
  while (t) {
    t--;
    solve();
  }
}
