using System;

public class Program

{

    public static void Main()

    {

        string a="some text";

        Console.WriteLine(a.Length);

        string b="some text";

        Console.WriteLine(b.IndexOf('t'));

        b=b.Insert(0,"Your");

        Console.WriteLine(a);

        a=a.Replace("This is", "I am");

        Console.WriteLine(a);

        string d="Paul Vincent";

        d=d.Insert(4,"eng");

        Console.WriteLine(d);

    }

}