using System;

using System.Collections.Generic;

public class Program

{

    private static void GetConnections(int[,] board,int x,int y,List<(int,int)> points, HashSet<(int,int)> ch)

    {

        if(ch.Add((x,y))==false)

            return;

        points.Add((x,y));

        var explodeVal=board[x,y];

        var width=board.GetLength(0);       

        var height=board.GetLength(1);

        if(x>0)

        {

            var left=board[x-1,y];

            if(left==explodeVal)

            GetConnections(board,x-1,y,points,ch);

        }

        if(x<width-1)

        {

            var right=board[x+1,y];

            if(right==explodeVal)

            GetConnections(board,x+1,y,points,ch);

        }

        if(y>0)

        {

            var top=board[x,y-1];

            if(top==explodeVal)

            GetConnections(board,x,y-1,points,ch);

        }

        if(y<height-1)

        {

            var bottom=board[x,y+1];

            if(bottom==explodeVal)

            GetConnections(board,x,y+1,points,ch);

        }

    }

    public static void Explode(int[,] board,int x,int y)

    {

        var width=board.GetLength(0);       

        var height=board.GetLength(1);

    }

​

    private static void MoveDownLine(int[,] board,int x)

    {

        var width=board.GetLength(0);       

        var q = new Queue<int>();

        for(var y=width-1;y>=0;y--)

        {

            var pt=board[y,x];

            if(pt!=0)

                q.Enqueue(pt);

        }

        for(var y=width-1;y>=0;y--)

        {

            var pt=board[y,x];

            if(q.TryDequeue(out var val))

                board[y,x]=val;

            else

                board[y,x]=0;

        }

    }

    private static void UpdateMap(int[,] board)

    {

        var d=board.GetLength(1);   

        for(var i=0;i<d;i++)

            MoveDownLine(board,i);

    }

    private static void PrintMap(int[,] board)

    {

        var height = board.GetLength(0);        

        var width = board.GetLength(1);

        for(var y=0;y<height;y++)

        {

            for(var x=0;x<width;x++)

                Console.Write(board[y,x]);

            Console.WriteLine();

        }

    }

    public static void Main()

    {

        var board=new int[,]

        {

            {0,0,1,0,0},

            {0,0,2,3,2},

            {0,2,2,2,2},

            {0,1,2,1,1},

        };

        PrintMap(board);

        var points = new List<(int,int)>();

        var ch = new HashSet<(int,int)>();

        GetConnections(board,2,2,points,ch);

        if(points.Count<4)

            return;

        foreach(var it in points)

        {

            board[it.Item1,it.Item2]=0;

        }

        UpdateMap(board);

        Console.WriteLine();

        PrintMap(board);

        //Console.WriteLine("Hello World");

    }

}