using System;

class Program
{
    static void Main ( string [] args )
    {

        NPC [] first = { new NPC(), new NPC (), new NPC (), new NPC () };
        Console.CursorVisible = false;

        while ( true )
        {
            foreach ( NPC npc in first)
            {
                RandomMove ( npc );
                Draw ( npc );
            }
        }
    }

    static void Draw ( NPC npc )
    {
        Console.SetCursorPosition (npc.x,npc.y);
        Console.Write ( '#' );
    }

    static void RandomMove ( NPC npc )
    {
        Random r = new Random ();
        npc.x += r.Next ( -2, 2 );
        npc.y += r.Next ( -2, 2 );
        if ( npc.x < 0 )
        { npc.x = 0; }
        if ( npc.x > Console.BufferWidth )
        { npc.x = Console.BufferWidth-1; }

        if ( npc.y < 0 )
        { npc.y = 0; }
        if ( npc.y > Console.BufferHeight )
        { npc.y = Console.BufferHeight-1; }
    }

    class NPC
    {
        public int x=0,y=0;
    }
}