#include <bits/stdc++.h>
using namespace std;
const int MAXN = 110;
int n, m, k;
int h[MAXN];
void load() {
  scanf("%d%d%d", &n, &m, &k);
  for (int i = 0; i < n; i++) scanf("%d", h + i);
}
bool solve() {
  long long sum = m;
  int ind = 0;
  while (ind < n - 1) {
    if (h[ind] >= h[ind + 1] - k) {
      int nxt = max(h[ind + 1] - k, 0);
      sum += h[ind] - nxt;
    } else {
      if (sum + h[ind] < h[ind + 1] - k) return false;
      sum -= h[ind + 1] - k - h[ind];
    }
    ind++;
  }
  return true;
}
int main() {
  int t;
  scanf("%d", &t);
  while (t--) {
    load();
    if (solve())
      printf("YES\n");
    else
      printf("NO\n");
  }
  return 0;
}
