#line 1 "main.cpp"
#include <iostream>
#include <vector>

using namespace std;

using lint = long long;

bool judge(int a, int b, int c) {
    if (a == c) return false;
    return (a < b && b > c) ||
           (a > b && b < c);
}

constexpr lint INF = 1LL << 50;

void solve() {
    int n;
    cin >> n;
    vector<int> xs(n);
    for (auto& x : xs) cin >> x;

    lint ans = -INF;
    for (int q = 0; q < 3; ++q) {
        vector<lint> dp(n + 1, -INF);
        dp[0] = 0;

        for (int i = 0; i < n; ++i) {
            dp[i + 1] = max(dp[i + 1], dp[i]);
            if (i + 2 < n &&
                judge(xs[i], xs[i + 1], xs[i + 2])) {
                dp[i + 3] = max(dp[i + 3], dp[i] + xs[i]);
            }
        }
        ans = max(ans, dp.back());

        xs.insert(xs.begin(), xs.back());
        xs.pop_back();
    }

    cout << ans << "\n";
}

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    int q;
    cin >> q;
    while (q--) solve();

    return 0;
}