/**
*    author:  shu8Cream
*    created: 29.01.2021 20:56:35
**/

#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for (int i=0; i<(n); i++)
#define all(x) (x).begin(), (x).end()
using ll = long long;
using P = pair<int,int>;
using vi = vector<int>;
using vvi = vector<vi>;

bool isKM(vi a){
    if(a[0]==a[1] || a[1]==a[2] || a[2]==a[0]) return false;
    if(max({a[0],a[1],a[2]})==a[1] ||  min({a[0],a[1],a[2]})==a[1]){
        return true;
    }
    return false;
}

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int t;
    cin >> t;
    while(t--){
        int n; cin >> n;
        vi a(n+2);
        rep(i,n) cin >> a[i];
        a[n]=a[0]; a[n+1]=a[1];
        ll ans = 0;
        rep(i,3){
            ll tmp = 0;
            for(int j=i; j<n; j+=3){
                vi b(3);
                b[0]=a[j]; b[1]=a[j+1], b[2]=a[j+2];
                if(isKM(b)) tmp+=a[j];
            }
            ans=max(ans, tmp);
        }
        cout << ans << endl;
    }
}