using System;

public class Program

{

    public static string Abbreviation(string inputstr)

{

    string abbr = "";

    int i = 0;

    abbr += inputstr[0];

    abbr += '.';

    for(i = 0; i < inputstr.Length - 1; i++)

    {

        if (inputstr[i] == ' ' || inputstr[i] == '\t' || 

            inputstr[i] == '\n')

        {

            abbr += inputstr[i + 1];

            abbr += '.';

        }

    }

    return abbr;

}

​

public static void Main()

{

    Console.WriteLine("First Name");

        String FirstName= Console.ReadLine();

    Console.WriteLine("Middle Name");

        String MiddleName= Console.ReadLine();

    Console.WriteLine("Last Name");

        String LastName= Console.ReadLine();

    string str = MiddleName;

    string abr = "";

    abr = Abbreviation(str);

  Console.Write("Full Name : "+FirstName+" "+abr+" "+LastName);

}

}