using System;

using System.Globalization;

using System.Linq;

using System.Text;

using System.Text.RegularExpressions;

public class Program

{

    public static void Main()

    {

        string a = NormalizeString("Ôra-Ôra-Ôra-Ôra-Ôra-Ôra-Ôra-Ôra-Ôra-Ôra-Ôra-Ôra-Ôra-Ôra-Ôra-Ôra-Ôra-Ôra");

        Console.WriteLine(a);

    }

    public static string NormalizeString(string cityName)

    {

        cityName = cityName.Normalize(NormalizationForm.FormD);

        var chars = cityName.Where(c => CharUnicodeInfo.GetUnicodeCategory(c) != UnicodeCategory.NonSpacingMark).ToArray();

        return RemoveSpecialChars(new string (chars).Normalize(NormalizationForm.FormC));

    }

​

    public static string RemoveSpecialChars(string cityName)

    {

        Regex rgx = new Regex("[^a-zA-Z]");

        return rgx.Replace(cityName, " ");

    }

}