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

bool kadomatsu(ll a, ll b, ll c) {
    if (a != b && b != c && c != a && (max({a, b, c}) == b || min({a, b, c}) == b)) return true;
    return false;
}
void solve() {
    ll n;
    cin >> n;
    vector<ll> a(n);
    rep(i, n) {
        cin >> a[i];
    }
    ll ans = 0;
    rep(i, 3) {
        vector<ll> b;
        rep(j, n) {
            b.push_back(a[(i + j) % n]);
        }
        vector<ll> dp(n + 1);
        rep(j, n + 1) {
            if (j != 0) {
                dp[j] = max(dp[j - 1], dp[j]);
            }
            if (j < n - 2 && kadomatsu(b[j], b[j + 1], b[j + 2])) {
                dp[j + 3] = max(dp[j + 3], dp[j] + b[j]);
            }
        }
        ans = max(ans, dp[n]);
    }
    cout << ans << endl;
}

int main() {
    ll t;
    cin >> t;
    while (t--) {
        solve();
    }
    return 0;
}