using System;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        int[][] Arr = new int[3][];

        Arr[0] = new int[3] { 1,0,3};

        Arr[1] = new int[3] { 4,0,6};

        Arr[2] = new int[3] { 7,8,9};

        int N =3;

        List<int> ArrIs = new List<int>();

        List<int> ArrJs = new List<int>();

        for (int i=0; i!= N; ++i)

        {

            for (int j=0; j!= N; ++j)

            {

                if(Arr[i][j] == 0)

                {

                    ArrIs.Add(i);

                    ArrJs.Add(j);

                }

            }

        }

        for (int i=0; i!= N; ++i)

        {

            for (int j=0; j!= N; ++j)

            {

                if(ArrIs.Contains(i) || ArrJs.Contains(j))

                    Arr[i][j] =0;

            }

            Console.WriteLine(Arr[i][0].ToString() + " " + Arr[i][1].ToString() + " " + Arr[i][2].ToString() );

        }

        //O(n2 + n2)= O(2n2)

    }

}