using System;

​

int[,] m = {

    { 1, 2, 3 },

    { 11, 0, 30 },

    { 5, -20, 55 },

    { 0, 0, -60 }

};

​

for (

        int i = 0,

        rows = m.GetLength(0),

        cols = m.GetLength(1); i < rows; i++)

{

    for (int j = 0; j < cols; j++)

    {

        if (m[i, j] < 0)

        {

            Console.WriteLine(m[i, j]);

            i = int.MaxValue - 1; // Break outer loop.

            break;

        }

    }

}