#include <bits/stdc++.h>
using namespace std;
int t, n, i, m, k, val;
int a[105];
bool ok;
int main() {
  cin >> t;
  while (t) {
    t--;
    cin >> n >> m >> k;
    ok = true;
    for (i = 1; i <= n; i++) {
      cin >> a[i];
    }
    for (i = 1; i < n; i++) {
      val = max(a[i + 1] - k, 0);
      if (a[i] >= val) {
        m += a[i] - val;
      } else {
        if (a[i] + m < val) {
          ok = false;
        } else {
          m -= val - a[i];
        }
      }
    }
    if (ok)
      cout << "YES\n";
    else
      cout << "NO\n";
  }
  return 0;
}
