T = int(input())
for _ in range(T):
    N = int(input())
    A = list(map(int,input().split()))
    A = A+A
    K0 = []
    for i in range(N-3+1):
        a,b,c = A[i:i+3]
        if a!=b and b!=c and c!=a and (max(a,b,c)==b or min(a,b,c)==b):
            K0.append(i)
    M0 = len(K0)
    dp0 = [0]*M0
    if M0>0:
        dp0[0] = A[K0[0]]
        for j in range(1,M0):
            dp0[j] = dp0[j-1]
            i0 = K0[j-1]
            i1 = K0[j]
            if i1>=i0+3:
                dp0[j] += A[i1]
    else:
        dp0 = [0]
    K1 = []
    for i in range(1,N-2+1):
        a,b,c = A[i:i+3]
        if a!=b and b!=c and c!=a and (max(a,b,c)==b or min(a,b,c)==b):
            K1.append(i)
    M1 = len(K1)
    dp1 = [0]*M1
    if M1>0:
        dp1[0] = A[K1[0]]
        for j in range(1,M1):
            dp1[j] = dp1[j-1]
            i0 = K1[j-1]
            i1 = K1[j]
            if i1>=i0+3:
                dp1[j] += A[i1]
    else:
        dp1 = [0]
    K2 = []
    for i in range(2,N-1+1):
        a,b,c = A[i:i+3]
        if a!=b and b!=c and c!=a and (max(a,b,c)==b or min(a,b,c)==b):
            K2.append(i)
    M2 = len(K2)
    dp2 = [0]*M2
    if M2>0:
        dp2[0] = A[K2[0]]
        for j in range(1,M2):
            dp2[j] = dp2[j-1]
            i0 = K2[j-1]
            i1 = K2[j]
            if i1>=i0+3:
                dp2[j] += A[i1]
    else:
        dp2 = [0]
    print(max(dp0[-1],dp1[-1],dp2[-1]))