using System;                   

​

public class Program

{

    struct _tableEntry{

        public readonly ulong point;

        public readonly decimal ord;

        public readonly string suffix;

        public _tableEntry(ulong point, decimal ord, string suffix)

        {

            this.point = point;

            this.ord = ord;

            this.suffix = suffix;

        }       

    }

    static _tableEntry [] table = new _tableEntry[] {

        new _tableEntry(1000L, 1, " B"), 

        new _tableEntry(1000000L, 1024m, " KB"), 

        new _tableEntry(1000000000L, 1048576m, " MB"), 

        new _tableEntry(1000000000000L, 1048576m * 1024, " GB"), 

        new _tableEntry(1000000000000000L, 1048576m * 1048576m, " TB"), 

        new _tableEntry(1000000000000000000L, 1048576m * 1048576m * 1024m, " PB") 

    };

    public static void Main()

    {

        ulong n = 1047420;      

        decimal ord = 1048576m * 1048576m * 1048576m;

        string suffix = "EB";

        for(int i=0;i<table.Length;++i)

        {

            if(n<table[i].point){               

                ord = table[i].ord;

                suffix = table[i].suffix;

                break;

            }

        }

        decimal k = n/ord;  

        Console.WriteLine(k);

        string circa = "";

        decimal formatted ;

        if(k < 10m)

        {           

            formatted = Math.Round(k, 2, System.MidpointRounding.AwayFromZero);

            if (Math.Abs(k - formatted) > 0.001m)

                circa = "~";

        }

        else if(k<100m){

            formatted = Math.Round(k, 1, System.MidpointRounding.AwayFromZero);

            if (Math.Abs(k - formatted) > 0.01m)

                circa = "~";

        }

        else {

            formatted = Math.Round(k, 0, System.MidpointRounding.AwayFromZero);

            if (Math.Abs(k - formatted) > 0.1m)

                circa = "~";

        }

        if(formatted < 10)

            Console.WriteLine(circa + formatted.ToString("0.##") + suffix);

        else if(formatted < 100)

            Console.WriteLine(circa + formatted.ToString("00.#") + suffix);

        else 

            Console.WriteLine(circa + formatted.ToString("000") + suffix);

    }

}