#include <iostream>

long long FindMax(int size, long long **A)
{
    long long max = 0;

    for (int j = 0; j < size; ++j)
    {
        if (A[0][size - 1] + A[1][j] > max)
        {
            max = A[0][size - 1] + A[1][j];
        }
        else
            if (A[0][size - 1] - A[2][j] > max)
            {
                max = A[0][size - 1] - A[2][j];
            }
    }

    return max;
}

void SetTables(int j, long long **A)
{
    if (j != 0)
    {
        if (A[1][j - 1] > 0)
        {
            A[1][j] = A[1][j - 1] + A[0][j];
        }
        else
        {
            A[1][j] = A[0][j];
        }

        if (A[2][j - 1] < 0)
        {
            A[2][j] = A[2][j - 1] + A[0][j];
        }
        else
        {
            A[2][j] = A[0][j];
        }

        A[0][j] += A[0][j - 1];
    }
    else
        if (j == 0)
        {
            A[1][j] = A[0][j];
            A[2][j] = A[0][j];
        }
}

int main()
{
    //std::ios_base::sync_with_stdio(0);
    //std::cin.tie(nullptr);
    //std::cout.tie(nullptr);

    long long n, m, max = 0;
    std::cin >> n;
    for (int i = 0; i < n; ++i)
    {
        std::cin >> m;
        long long ** T = new long long * [3];
        T[0] = new long long[m];
        T[1] = new long long[m];
        T[2] = new long long[m];
        for (int j = 0; j < m - 1; ++j)
        {
            std::cin >> T[0][j];
            SetTables(j, T);
        }
        std::cout << FindMax(m - 1, T) << "\n";
        delete [] T[0], T[1], T[2], T;
    }
    return 0;
}