#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
using namespace std;

typedef long long ll;

ll mod_pow(ll x, ll n, ll mod) {
    ll res = 1;
    while (n > 0) {
        if (n & 1) res = res * x % mod;
        x = x * x % mod;
        n >>= 1;
    }
    return res;
}

int main() {
    int T;
    cin >> T;
    while (T-- > 0) {
        int N;
        cin >> N;
        vector<int> A(N + 2);
        rep(i, N) cin >> A[i];
        A[N] = A[0];
        A[N + 1] = A[1];
        ll ans = 0;
        rep(i, 3) {
            vector<ll> dp(N + 1, 0);
            rep (j, N) {
                dp[j + 1] = max(dp[j + 1], dp[j]);
                if (j < N - 2 && 1LL * (A[j + i] - A[j + i + 1]) * (A[j + i + 1] - A[j + i + 2]) < 0 && A[j + i] != A[j + i + 2]) {
                    dp[j + 3] = max(dp[j + 3], dp[j] + A[j + i]);
                }
            }
            //rep(j, N + 1) cout << dp[j] << " "; cout << "\n";
            ans = max(ans, dp[N]);
        }
        cout << ans << "\n";
    }
}