#include <bits/stdc++.h>
using namespace std;
int main() {
  int p;
  cin >> p;
  while (p--) {
    int n, m, k, x = 1;
    cin >> n >> m >> k;
    int a[n];
    for (int i = 0; i < n; i++) {
      cin >> a[i];
    }
    for (int i = 0; i < n - 1; i++) {
      m = m + ((k >= a[i + 1]) ? a[i] : (a[i] + k - a[i + 1]));
      if (m < 0) {
        x = -1;
        break;
      }
    }
    if (x == -1) cout << "NO" << endl;
    if (x == 1) cout << "YES" << endl;
  }
  return 0;
}
