T = int(input())
INFTY = 10**14
for _ in range(T):
    N = int(input())
    A = [0]+list(map(int,input().split()))
    B = [0 for _ in range(N+1)]
    for i in range(1,N+1):
        B[i] = B[i-1]+A[i]
    ans = -INFTY
    for s1 in [-1,1]:
        for s2 in [-1,1]:
            for s3 in [-1,1]:
                B1 = [(s1-s2)*B[i] for i in range(N+1)]
                C = [-INFTY for _ in range(N+1)]
                C[2] = B1[1]
                for i in range(3,N):
                    C[i] = max(C[i-1],B1[i-1])
                for j in range(2,N):
                    ans = max(ans,C[j]+(s2-s3)*B[j]+s3*B[N])
    print(ans)