def solve(A):
    DP=[0]*(N+3)
    for i in range(N-2):
        DP[i]=max(DP[i-1],DP[i])

        if A[i]>A[i+1] and A[i+1]<A[i+2] and A[i]!=A[i+2]:
            DP[i+3]=max(DP[i+3],DP[i]+A[i])

        if A[i]<A[i+1] and A[i+1]>A[i+2] and A[i]!=A[i+2]:
            DP[i+3]=max(DP[i+3],DP[i]+A[i])

    return max(DP)
        
        

T=int(input())
for tests in range(T):
    N=int(input())
    A=list(map(int,input().split()))

    M1=solve(A)

    A=A[1:]+[A[0]]

    M2=solve(A)

    A=A[1:]+[A[0]]

    M3=solve(A)

    A=A[1:]+[A[0]]

    M4=solve(A)

    print(max(M1,M2,M3,M4))