using System;

using System.Text;

using System.Diagnostics;

public class Program

{

    public static void Main()

    {

        string a = new String('a', 10000);

        string b = new String('b', 15000);

        string c = "c";

        Stopwatch stopWatch = new Stopwatch();

        stopWatch.Start();

        string joinedString = null;

        var builder = new StringBuilder(a);

        builder.Append(b);

        builder.ToString();

        stopWatch.Stop();

        Console.WriteLine(stopWatch.Elapsed);

        stopWatch.Reset();

        stopWatch.Start();

        joinedString = a + b;

        stopWatch.Stop();

        Console.WriteLine(stopWatch.Elapsed);

        bool result;

        stopWatch.Reset();

        stopWatch.Start();

        result = String.Compare(joinedString, c, false) == 0;

        stopWatch.Stop();

        Console.WriteLine(stopWatch.Elapsed);

        stopWatch.Reset();

        stopWatch.Start();

        result = joinedString.Equals(c, StringComparison.CurrentCultureIgnoreCase);

        stopWatch.Stop();

        Console.WriteLine(stopWatch.Elapsed);

    }

}