You are given an array $a$ of $n$ positive integers.

You can use the following operation as many times as you like: select any integer $1 \le k \le n$ and do one of two things:   decrement by one $k$ of the first elements of the array.  decrement by one $k$ of the last elements of the array. 

For example, if $n=5$ and $a=[3,2,2,1,4]$, then you can apply one of the following operations to it (not all possible options are listed below):   decrement from the first two elements of the array. After this operation $a=[2, 1, 2, 1, 4]$;  decrement from the last three elements of the array. After this operation $a=[3, 2, 1, 0, 3]$;  decrement from the first five elements of the array. After this operation $a=[2, 1, 1, 0, 3]$; 

Determine if it is possible to make all the elements of the array equal to zero by applying a certain number of operations.


-----Input-----

The first line contains one positive integer $t$ ($1 \le t \le 30000$) — the number of test cases. Then $t$ test cases follow.

Each test case begins with a line containing one integer $n$ ($1 \le n \le 30000$) — the number of elements in the array.

The second line of each test case contains $n$ integers $a_1 \ldots a_n$ ($1 \le a_i \le 10^6$).

The sum of $n$ over all test cases does not exceed $30000$.


-----Output-----

For each test case, output on a separate line:   YES, if it is possible to make all elements of the array equal to zero by applying a certain number of operations.  NO, otherwise. 

The letters in the words YES and NO can be outputed in any case.


-----Example-----
Input
4
3
1 2 1
5
11 7 9 6 8
5
1 3 1 3 1
4
5 2 1 10

Output
YES
YES
NO
YES

```python

USER_FILENAME = "<user_code>"
import sys, json, builtins
import math, heapq, bisect, itertools, functools, collections, statistics, fractions, decimal, operator, array, random, re, string, os, pathlib
try:
    import resource as _res
except Exception:
    _res = None
from collections import Counter, defaultdict, deque, OrderedDict
from functools import lru_cache, reduce
from itertools import accumulate, permutations, combinations, product
from math import gcd, ceil, floor, sqrt
from decimal import Decimal
try:
    from typing import *
except Exception:
    pass
try:
    sys.setrecursionlimit(1_000_000)
except Exception:
    pass
try:
    import site as _site
    try:
        _sys_sites = _site.getsitepackages() if hasattr(_site, "getsitepackages") else []
        for _p in _sys_sites:
            if _p and _p not in sys.path:
                sys.path.append(_p)
    except Exception:
        pass
    try:
        _usp = _site.getusersitepackages()
        if isinstance(_usp, str):
            _usp = [_usp]
        for _p in _usp:
            if _p and _p not in sys.path:
                sys.path.append(_p)
    except Exception:
        pass
except Exception:
    pass

ns = {"__name__": "__main__"}
for _k, _v in list(globals().items()):
    if not _k.startswith("_"):
        ns[_k] = _v
_CODE = 'import sys\ninput = sys.stdin.readline\n\ndef main():\n    n = int(input())\n    alst = list(map(int, input().split()))\n    up = alst[0]\n    down = 0\n    for a in alst[1:]:\n        if (up + down) == a:\n            continue\n        elif (up + down) < a:\n            down = a - up\n        else:\n            up = a - down\n        if up < 0 or down < 0:\n            print("NO")\n            return\n    print("YES")\n        \n    \n    \nfor _ in range(int(input())):\n    main()'
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

```

Measured memory_bytes: 13067