#include <bits/stdc++.h>
using namespace std;
const int NMAX = 1e2 + 1;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int T;
  cin >> T;
  int n, m, k;
  int arr[NMAX];
  while (T--) {
    cin >> n >> m >> k;
    for (int i = 0; i < n; i++) {
      cin >> arr[i];
    }
    bool finished = true;
    for (int i = 0; i < n - 1; i++) {
      int diff = arr[i + 1] - arr[i];
      if (diff > k) {
        m -= diff - k;
        if (m < 0) {
          finished = false;
          break;
        }
      } else {
        m += min(arr[i], k - diff);
      }
    }
    if (finished) {
      cout << "YES\n";
    } else {
      cout << "NO\n";
    }
  }
  return 0;
}
