How can I get the sum of numbers from a diagonal line?
<p>Here is the sum for a diagonal top-left to bottom-right:</p>

<pre><code>public int sumarDiagonal()
{
    int x = 0;
    for (int F = 0; F &lt; Filas; F++)
    {
        for (int c = 0; c &lt; Columnas; c++)
        {
            if (F == c)
            {
                x += m[F,c];
            }
        }
    }
    return x;
}
</code></pre>

<p>How can I go from top-right to bottom-left?</p>
