using System;

public class Program

{

    public static void Main()

    { 

     int [] x={1,2,0,0,4,0};

     int k=0;

     for(int i=0;i<x.Length-k;i++)

     {

       if(x[i]==0)

       {

           for(int j=i; j<x.Length-1;j++)

         {

          x[j]=x[j+1];

         }

           x[x.Length-1]=0;

          if(i>0)i--;

           k++;

       }

     }

        Console.WriteLine(x);

    }

}