C

#include <bits/stdc++.h>

using namespace std;

#define ll     long long
#define _test   int _TEST; cin>>_TEST; while(_TEST--)

int main()
{
    _test
    {
        int n;
        cin>>n;

        vector<ll int> a(n);
        for(auto &e: a)     cin>>e;

        if(n == 1)
        {
            if(a[0] <= 0)       cout<<0<<"\n";
            else                cout<<a[0]<<"\n";

            continue;
        }

        ll int ans = 0;

        if(a[0]>=0 || a[1]<=0)
        {
            for(int i=0; i<n; i++)
                ans += max(0ll, a[i]);

            cout<<ans<<"\n";

            continue;
        }

        for(int i=2; i<n; i++)
            ans += max(0ll, a[i]);

        ans += max(0ll, a[0]+a[1]);

        cout<<ans<<"\n";
    }
}