#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;
using ll = long long;
ll kado(int a , int b , int c){
    if(a == b || b == c || c == a){
        return 0;
    }
    if(b < a && b < c){
        return a;
    }
    if(b > a && b > c){
        return a;
    }
    return 0;
}

void solve(){
  int n;
  cin >> n;
  vector<ll> a(n);
  for(int i = 0; i < n; i++){
      cin >> a[i];
  }
  a.push_back(a[0]);
  a.push_back(a[1]);

  vector<ll> KadoTable(n + 2 , 0);
  KadoTable[0] = 0;
  KadoTable[1] = 0;
  for(int i = 2; i < n + 2; i++){
      KadoTable[i] = kado(a[i - 2] , a[i - 1] , a[i]);
  }
  vector<ll> dp(n + 2 , 0);
  dp[0] = KadoTable[0];
  dp[1] = KadoTable[1];
  dp[2] = KadoTable[2];
  for(int i = 3; i < n + 2; i++){
      dp[i] = max(KadoTable[i] + KadoTable[i - 3] , KadoTable[i - 1]);
  }
  cout << dp[n + 1] << endl;
}
int main() {
    int t;
    cin >> t;
    for(int i = 0; i < t; i++)solve();
    return 0;
}