#include<bits/stdc++.h>
using namespace std;
using ll = long long int;
using ld = long double;
const ll MAX = 50000000000000;
ll MOD = 1000000007;
bool isK(ll a,ll b,ll c){
    return a != b && a != c && b != c && ((a < b && c < b) || (a > b && c > b));
}
int main(){
    ll T,t;
    cin >> T;
    for(t = 0;t < T;t++){
        ll N,i;
        cin >> N;
        vector<ll> A(N),B(N,0),DPA(N + 10,0),DPB(N + 10,0),DPC(N + 10,0);
        for(i = 0;i < N;i++) cin >> A[i];
        for(i = 0;i < N;i++) B[i] = isK(A[i],A[(i + 1) % N],A[(i + 2) % N]) * A[i];
        for(i = 0;i < N;i++){
            DPA[i + 1] = max(DPA[i + 1],DPA[i]);
            DPA[i + 3] = max(DPA[i + 3],DPA[i] + B[i]);
        }
        B.emplace_back(B[0]);
        B.erase(B.begin());
        for(i = 0;i < N;i++){
            DPB[i + 1] = max(DPB[i + 1],DPB[i]);
            DPB[i + 3] = max(DPB[i + 3],DPB[i] + B[i]);
        }
        B.emplace_back(B[0]);
        B.erase(B.begin());
        for(i = 0;i < N;i++){
            DPC[i + 1] = max(DPC[i + 1],DPC[i]);
            DPC[i + 3] = max(DPC[i + 3],DPC[i] + B[i]);
        }
        cout << max({DPA[N],DPB[N],DPC[N]}) << endl;
    }
}