import bisect, collections, copy, heapq, itertools, math, string
import sys
def I(): return int(sys.stdin.readline().rstrip())
def MI(): return map(int, sys.stdin.readline().rstrip().split())
def LI(): return list(map(int, sys.stdin.readline().rstrip().split()))
def S(): return sys.stdin.readline().rstrip()
def LS(): return list(sys.stdin.readline().rstrip().split())
from collections import deque
from collections import Counter
from collections import defaultdict
import bisect
from functools import reduce
from functools import lru_cache
sys.setrecursionlimit(1000000)
MOD = 10 ** 9 + 7
MOD99 = 998244353
INF = 10 ** 20

def main():
    T = I()
    for _ in range(T):
        N = I()
        A = LI()
        dp = [[[-INF] * 2 for _ in range(3)] for _ in range(N+1)]
        dp[0][0][0] = 0
        dp[1][0][0], dp[1][0][1] = A[0], -A[0]
        for i in range(1, N):
            for j in range(3):
                for k in range(2):
                    if dp[i][j][k] <= -INF:
                        continue
                    for nj in range(j, 3):
                        for nk in range(2):
                            if nj - j >= 2:
                                continue
                            if j == nj:
                                if k != nk:
                                    continue
                                if k == 0:
                                    dp[i+1][nj][nk] = max(dp[i+1][nj][nk], dp[i][j][k] + A[i])
                                else:
                                    dp[i + 1][nj][nk] = max(dp[i + 1][nj][nk], dp[i][j][k] - A[i])
                            else:
                                if k == 0:
                                    dp[i + 1][nj][nk] = max(dp[i + 1][nj][nk], dp[i][j][k] + A[i])
                                else:
                                    dp[i + 1][nj][nk] = max(dp[i + 1][nj][nk], dp[i][j][k] - A[i])
        print(max(dp[-1][2]))
        # print(dp)
if __name__ == "__main__":
    main()