#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef pair<ll,ll> P;
typedef vector<ll> VI;
typedef vector<VI> VVI;
#define REP(i,n) for(int i=0;i<(n);i++)
#define ALL(v) v.begin(),v.end()
constexpr ll MOD=1000000007;
constexpr ll INF=1e18;

bool kad(int a, int b, int c){
    if(a==c)
        return 0;
    if(a>b&&b<c)
        return 1;
    if(a<b&&b>c)
        return 1;
    return 0;
}

int main(){
    int t; cin >> t;
    while(t--){
        int n; cin >> n;
        VI a(n); REP(i,n) cin >> a[i];
        ll ans=0;
        REP(k,3){
            VI dp(n*3,0);
            REP(i,n-2){
                dp[k+i+3]=max(dp[k+i+3],dp[k+i+2]);
                if(kad(a[(k+i)%n],a[(k+i+1)%n],a[(k+i+2)%n])){
                    dp[k+i+3]=max(dp[k+i+3],dp[k+i]+a[(k+i)%n]);
                }
            }
            ans=max(ans,dp[k+n]);
        }
        cout << ans << endl;
    }
    return 0;
}