t = int(input())
for _ in range(t):
    n = int(input())
    A = list(map(int, input().split()))
    maxA = max(A)
    C = []
    for i in range(n):
        if A[i] == maxA:
            C.append(i)
    if len(C) == n:
        print(0)
    elif len(C) == 1:
        idx = C[0]
        ans = sorted(set(A), reverse=True)[1]
        for i in range(1, n):
            ii = (idx + i) % n
            if A[(ii - 1) % n] - A[ii] <= 0:
                ans = maxA
                break
        print(ans)