import sys
from collections import defaultdict, Counter, deque
from itertools import permutations, combinations, product, combinations_with_replacement, groupby, accumulate
import operator
#from math import sqrt,isqrt
#from bisect import bisect_left,bisect_right
#from functools import lru_cache,reduce
#import heapq
#import numpy as np
#import networkx as nx
# from numba import njit, b1, i1, i4, i8, f8
# numba例 @njit(i1(i4[:], i8[:, :]),cache=True) 引数i4配列、i8 2次元配列,戻り値i1
def input(): return sys.stdin.readline().rstrip()
def divceil(n, k): return 1+(n-1)//k  # n/kの切り上げを返す


def check(a):
    return len(set(a)) == 3 and a[1] in [max(a), min(a)]

def solve(n,a):
    value=[0]*n
    for i in range(n):
        if check([a[i-2],a[i-1],a[i]]):
            value[i-2]=a[i-2]
    ans=0
    for i in range(3):
        dp=[0]*(n+1)
        for j in range(2,n):
            dp[j]=max(dp[j-1],dp[j-3]+value[j])
        ans=max(dp[-2],ans)
        num=value.pop(0)
        value.append(num)
    return ans




def main():
    mod = 10**9+7
    mod2 = 998244353
    t=int(input())
    for i in range(t):
        n=int(input())
        print(solve(n,list(map(int, input().split()))))
    


if __name__ == '__main__':
    main()