#include <bits/stdc++.h>
using namespace std;
inline void read(int &x) {
  int v = 0, f = 1;
  char c = getchar();
  while (!isdigit(c) && c != '-') c = getchar();
  if (c == '-')
    f = -1;
  else
    v = (c & 15);
  while (isdigit(c = getchar())) v = (v << 1) + (v << 3) + (c & 15);
  x = v * f;
}
inline void read(long long &x) {
  long long v = 0ll, f = 1ll;
  char c = getchar();
  while (!isdigit(c) && c != '-') c = getchar();
  if (c == '-')
    f = -1;
  else
    v = (c & 15);
  while (isdigit(c = getchar())) v = (v << 1) + (v << 3) + (c & 15);
  x = v * f;
}
inline void readc(char &x) {
  char c;
  while (((c = getchar()) == ' ') || c == '\n')
    ;
  x = c;
}
int n, m, i, j, t, a[30005];
long long s0, s1;
int main() {
  read(t);
  while (t--) {
    read(n);
    for (((i)) = (1); ((i)) <= ((n)); ((i))++) read(a[i]);
    a[n + 1] = 0;
    for (((i)) = ((n + 1)); ((i)) >= (1); ((i))--) a[i] = a[i] - a[i - 1];
    s0 = a[1];
    s1 = a[n + 1];
    for ((i) = (2); (i) <= (n); (i)++)
      if (a[i] > 0)
        s1 += a[i];
      else
        s0 += a[i];
    if (s1 <= 0 && s0 >= 0)
      puts("YES");
    else
      puts("NO");
  }
  return 0;
}
