def is_kadomatsu(l):
    return len(set(l)) == 3 and (min(l) == l[1] or max(l) == l[1])
for _ in range(int(input())):
    n = int(input())
    a = list(map(int, input().split())) * 2
    l = [(a[i], i) for i in range(2 * n)]
    l.sort(key=lambda x:x[1])
    l.sort(key=lambda x:x[0], reverse=True)
    visited = [0] * n
    ans = 0
    for i in range(2 * n):
        v, ind = l[i]
        try:
            if all(not visited[(ind + j) % n] for j in range(3)) and is_kadomatsu(a[ind:ind + 3]):
                for j in range(3):
                    visited[(ind + j) % n] = 1
                ans += v
        except:
            pass
    print(ans)