using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        String a = "ba" + '\u00f1' + "ana";

        String b = "ban" + '\u0303' + "ana";

        Console.WriteLine(a == b);

        Console.WriteLine(string.Equals(a, b, StringComparison.InvariantCulture));

        Console.WriteLine(string.Equals(a, b, StringComparison.CurrentCulture));

        var set = new HashSet<string>();

        Console.WriteLine(set.Add(a));

        Console.WriteLine(set.Add(a));

    }

}