#include <bits/stdc++.h>
using namespace std;
const long long N = 30000;
long long t, n, a[N], l, r;
bool possible() {
  if (l > r) return 1;
  long long o = a[l - 1];
  a[l - 1] = 0;
  for (long long i = l; i <= r; i++) {
    long long v = max(a[i - 1], a[i] - o);
    if (v > a[r + 1]) return 0;
    o = a[i] - v;
    a[i] = v;
  }
  return 1;
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cin >> t;
  while (t--) {
    cin >> n;
    for (long long i = 0; i < n; i++) cin >> a[i];
    l = 1;
    r = n - 2;
    for (; l < n && a[l - 1] >= a[l]; l++)
      ;
    for (; r >= 0 && a[r] <= a[r + 1]; r--)
      ;
    cout << (possible() ? "YES\n" : "NO\n");
  }
}
