// Find the best total from entry [x, y] to the top.
BestTotal(int[,] array, int x, int y)
{
    // Start with the value from this entry.
    int total = array[x, y];

    // If we're at the top, then we're done.
    if (y == 0) return total;

    // Try up and to the left.
    int best_total = 0;
    int test_total = 0;
    if (x > 0)
    {
        test_total = BestTotal(array, x - 1, y - 1);
        if (test_total > best_total) best_total = test_total;
    }

    // Try straight up.
    if (x <= {maximum x coordinate in row y - 1})
    {
        test_total = BestTotal(array, x, y - 1);
        if (test_total > best_total) best_total = test_total;
    }

    // Try up and to the right.
    if (x + 1 <= {maximum x coordinate in row y - 1})
    {
        test_total = BestTotal(array, x + 1, y - 1);
        if (test_total > best_total) best_total = test_total;
    }

    // Add the best value to our value and return it.
    return total + best_value;
}