using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

​

public class Program

{

        class  access

{

    public string name;

    public void print()

    { Console.WriteLine("\nMy name is"+name); }

}

public static int basepow;

    static int power(int po)

    {

        if(po==0)

        {

            return 1;

        }

        else

            return basepow*power(po -1);

    }

static int Fact(int n1)

{

    if(n1<=1)

    {

        return 1;

    }

        else

        {

            return n1*Fact(n1-1);

        }

}

    public static void Main()

    {

        int opt;    

        string a;

        label:

        Console.WriteLine("----Бодлогын дугаараа оруулна уу");

        opt=Convert.ToInt32(Console.ReadLine());

        switch (opt)

        {

            case 1:

            //-Бодлого 1 -------

              Console.WriteLine("====Бодлого1==");

        string str1; string str2;

        str1= "Health university"; str2="Medical unversity";

        Console.WriteLine(str1.Contains("hiin"));

        Console.WriteLine(str1.EndsWith("n"));

        Console.WriteLine(str1.Equals(str2));

        Console.WriteLine(str1.GetType());

        Console.WriteLine(str1.IndexOf("n"));

        Console.WriteLine(str1.ToLower());

        Console.WriteLine(str1.ToUpper());

        Console.WriteLine(str1.Insert(0,"sain uu"));

        Console.WriteLine(str1.LastIndexOf("a"));

        Console.WriteLine(str1.Length); 

        Console.WriteLine(str1.Remove(5));

        Console.WriteLine(str1.Replace('a','y'));

        string[] split= str1.Split(new char[] {'a'});

        Console.WriteLine(split[0]); Console.WriteLine(split[1]);

        Console.WriteLine(str1.StartsWith("S"));

        Console.WriteLine(str1.Substring(2,5));

        Console.WriteLine(str1.ToCharArray());

        Console.WriteLine(str1.Trim());

        break;  

            break;

            case 2:

            //-Бодлого2 -------

            Console.WriteLine("----Бодлого 2 -------"); 

                access ac=new access();

                Console.Write("Enter your name:\t");

                ac.name=Console.ReadLine(); ac.print();

            break;

            case 3:

            //-Бодлого3 -------

            Console.WriteLine("----Бодлого 3 -------");     

                Console.Write("power:");

                int pow=Convert.ToInt32(Console.ReadLine());

                Console.Write("base of power:");

                basepow=Convert.ToInt32(Console.ReadLine());

                int n=power(pow);

                Console.WriteLine("Result:{0}",n);

                break ; 

            case 4:

            //-Бодлого -------

            Console.WriteLine("----Бодлого 4-------");      

                Console.Write("Enter a Number to find factorial:");

                int n1=Convert.ToInt32(Console.ReadLine());

                int r=Fact(n1);

                    Console.WriteLine(n1.ToString()+"!="+r.ToString());

                break ; 

            default: Console.WriteLine("----Буруу дугаар байна -------");   goto label;

        }

        Console.WriteLine("----Дахин эхлүүлэх бол y товчийг дарна уу -------");

        a=Console.ReadLine();

        if (a=="y") {goto label;}

    }

}