using System;

using System.Linq;

public class Program

{

    public static void Main()

    {

        Console.WriteLine(HiddenString("Samet Öz" , '/'));

    }

    public static string HiddenString(string target, char hiddenChar)

    {

        string result = string.Empty;

        if(target.Length == 0) return "Hata";

        string replacedString = target.Substring(1,target.Length - 1);

        string firstStr = target.Substring(0,1);

        replacedString = new String(replacedString.Select(r => r == ' ' ? ' ' : hiddenChar).ToArray());

        return String.Format("{0}{1}",firstStr,replacedString);

    }

}