#include<bits/stdc++.h>
// #include<atcoder/all>

using namespace std;
// using namespace atcoder;
using ll = long long;
using ull = unsigned long long;
using P = pair<int,int>;
#define rep(i,n) for(ll i = 0;i < (ll)n;i++)
#define ALL(x) (x).begin(),(x).end()
#define MOD 1000000007


int main(){
  
  int T;
  cin >> T;
  while(T--){
    int n;cin >> n;
    vector<int> a(n);
    rep(i,n)cin >> a[i];
    rep(i,3)a.push_back(a[i]);
    auto solve = [&](int s){
      vector<ll> dp(n+10);
      for(int i = s+2;i < n+s;i++){
        dp[i] = max(dp[i],dp[i-1]);
        int k = 0;
        if(i-3 >= 0)k = dp[i-3];
        if(a[i-2] != a[i-1] && a[i-1] != a[i] && a[i-2] != a[i] && (*min_element(a.begin()+i-2,a.begin()+i+1) == a[i-1] || *max_element(a.begin()+i-2,a.begin()+i+1) == a[i-1])){
          dp[i] = max(dp[i],1ll*k + a[i-2]);
        }
      }
      return dp[n+s-1];
    };
    cout << max({solve(0),solve(1),solve(2)}) << "\n";
  }
  

  return 0;
}