#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <queue>
#include <string>
#include <map>
#include <set>
#include <stack>
#include <tuple>
#include <deque>
#include <array>
#include <numeric>
#include <bitset>
#include <iomanip>
#include <cassert>
#include <chrono>
#include <random>
#include <limits>
#include <iterator>
#include <functional>
#include <sstream>
#include <fstream>
#include <complex>
#include <cstring>
#include <unordered_map>
#include <unordered_set>
using namespace std;

using ll = long long;
constexpr int INF = 1001001001;
constexpr int mod = 1000000007;
// constexpr int mod = 998244353;

template<class T>
inline bool chmax(T& x, T y){
    if(x < y){
        x = y;
        return true;
    }
    return false;
}
template<class T>
inline bool chmin(T& x, T y){
    if(x > y){
        x = y;
        return true;
    }
    return false;
}

void solve(){
    int N;
    cin >> N;
    vector<int> A(N);
    for(int i = 0; i < N; ++i)  cin >> A[i];
    ll ans = 0;
    for(int k = 0; k < 3; ++k){
        vector<ll> dp(N + 10);
        for(int i = 0; i + 2 < N; ++i){
            int l = (i + k) % N, m = (i + k + 1) % N, r = (i + k + 2) % N;
            chmax(dp[l + 1], dp[l]);
            if((A[l] < A[m] && A[m] > A[r]) || (A[l] > A[m] && A[m] < A[r])){
                if(A[l] != A[r])    chmax(dp[l + 3], dp[l] + A[l]);
            }
        }
        chmax(ans, *max_element(begin(dp), end(dp)));
    }
    cout << ans << '\n';
}
int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

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

    return 0;
}