#include <bits/stdc++.h>
using namespace std;
#define fastio() ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL)
#define LSB(i) ((i) & (-i))
#define ll long long
const int dx[]{-1,1,0,0,-1,-1,1,1};
const int dy[]{0,0,1,-1,-1,1,-1,1};
const int MOD = 1e9+7;
const int inf = 1e9+1; 


#define int ll

void solve(int testCase)  {
    int n; cin >> n;
    vector<int>v(n);
    for(int& x : v) cin >> x;
    int sum = -1e18, mx = -1e18, j = -1;
    for(int i = 0; i < n; ++i){
        if(v[i] > sum+v[i]){
            sum = v[i];
            j = i;
        } else sum += v[i];
        if((i-j+1)&1) mx = max(mx, sum);
        else mx = max(mx, max(sum-v[j], sum-v[i]));
    }
    cout << mx << '\n';
}   

int32_t main(){
    fastio();  
    int t = 1;
    cin >> t;
    for(int i = 1; i <= t; ++i){
        solve(i);
    }
    return 0;
}