#include <bits/stdc++.h>
using namespace std;
int t;
bool er = 0;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cin >> t;
  while (t--) {
    bool ans = 0;
    int n, m, k, a[110];
    cin >> n >> m >> k;
    for (int i = 1; i <= n; ++i) cin >> a[i];
    for (int i = 1; i < n; ++i) {
      if (a[i] < a[i + 1]) {
        if (a[i + 1] - a[i] <= k) {
          int can = k - (a[i + 1] - a[i]);
          m += min(a[i], can);
          continue;
        }
        if (a[i + 1] - a[i] - k <= m)
          m -= max(0, a[i + 1] - a[i] - k);
        else {
          ans = 1;
          break;
        }
      } else
        m += a[i] - max(0, a[i + 1] - k);
    }
    if (ans)
      puts("NO");
    else
      puts("YES");
  }
}
