How do I return the largest value (after total) in 2D array?

Hi, 

I am trying to find the largest value in a 2D array. The 2D array has been populated with numbers that has been entered by users. Each row represents a 'topic'. The function below should loop through the array starting with its row and 10 columns and totalling the result. 

Please note: I am going through an old C++ book that uses arrays as opposed to improved containers.

Thank you in advance!! :)

int getHighest(int arr[][10])
{
    int total = 0;
    int index;
    int largest = 0;
    
    for (int i = 0; i < 5; i++)
    {
        for (int j = 0; j < 10; j++)
        {
            if (responses[i][j] >= 1)
            {
                index = j + 1;
                total += (index * (responses[i][j]));
            }
        }
        if (total > largest)
        {
            largest = total;
        }
    }

    return largest;
}