Here is my code:

using System;
using System.Collections;
using System.IO;

namespace problem1001
{
    class mySolution
    {
        static void Main()
        {
            Stream myStream = Console.OpenStandardInput();
            Stack myNumbers = new Stack();
            string buffer = "";
            int temp;
            while (true)
            {
                temp = myStream.ReadByte();
                if (char.IsDigit((char)temp))
                    buffer += (char)temp;
                else
                {
                    if (buffer != "")
                    {
                        myNumbers.Push(double.Parse(buffer));
                        buffer = "";
                    }
                    if (temp == -1)
                        break;
                }
            }
            while (myNumbers.Count != 0)
            {
                Console.WriteLine("{0:f4}", Math.Sqrt((double)myNumbers.Pop()));
            }
        }
    }
}