#include <bits/stdc++.h>
using namespace std;
const int mod = 1e9 + 7;
const long long N = 1e5 + 5;
long long a[N];
bool dp[N];
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int t;
  cin >> t;
  while (t--) {
    long long n, m, k;
    cin >> n >> m >> k;
    for (int i = 0; i < n; i++) {
      cin >> a[i];
    }
    long long tmp = m;
    dp[0] = true;
    for (int i = 1; i < n; i++) {
      if (!dp[i - 1])
        dp[i] = false;
      else {
        long long h = 0;
        long long tm = max(h, a[i] - k);
        tmp += a[i - 1] - tm;
        if (tmp >= 0) {
          dp[i] = true;
        } else
          dp[i] = false;
      }
    }
    if (!dp[n - 1])
      cout << "NO" << endl;
    else
      cout << "YES" << endl;
  }
  return 0;
}
