#include <bits/stdc++.h>
using namespace std;
int main() {
  long long T;
  cin >> T;
  while (T--) {
    long long n, m, k, flag = 0;
    cin >> n >> m >> k;
    long long h[105] = {0};
    for (long long i = 0; i < n; i++) {
      cin >> h[i];
    }
    for (long long i = 0; i < n - 1; i++) {
      if (h[i] >= h[i + 1]) {
        if (k >= h[i + 1]) {
          m += h[i];
        } else {
          m += (k + abs(h[i] - h[i + 1]));
        }
      } else {
        if (k >= h[i + 1]) {
          m += h[i];
        } else if (k >= abs(h[i] - h[i + 1])) {
          m += (k - abs(h[i] - h[i + 1]));
        } else {
          m -= (abs(h[i] - h[i + 1]) - k);
          if (m < 0) {
            flag = 1;
            break;
          }
        }
      }
    }
    if (flag == 0)
      cout << "YES" << endl;
    else
      cout << "NO" << endl;
  }
  return 0;
}
