#include <bits/stdc++.h>
using namespace std;
typedef complex<long double> point;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int t;
  cin >> t;
  while (t--) {
    int n, m, k, h[111];
    cin >> n >> m >> k;
    for (int i = 0; i < n; i++) cin >> h[i];
    int is = 1;
    for (int i = 0; (i < (n - 1)) & is; i++) {
      int perfect = max(0, h[i + 1] - k);
      if (h[i] >= perfect)
        m += (h[i] - perfect);
      else {
        if ((perfect - h[i]) <= m)
          m -= (perfect - h[i]);
        else
          is = 0;
      }
    }
    if (is)
      cout << "YES\n";
    else
      cout << "NO\n";
  }
  return 0;
}
