using System;

using System.Globalization;

using System.Text.RegularExpressions;

​

public class Program

{

    public static void Main()

    {

        var input = "I like working at NTT Data.";

        var output = CapitalizeWords(input);        

        Console.WriteLine(output);

        var output2 = CapitalizeWords2(input);      

        Console.WriteLine(output2);

    }

    public static string CapitalizeWords(string input)

    {

        return CultureInfo.CurrentCulture.TextInfo.ToTitleCase(input.ToLower());

    }

    public static string CapitalizeWords2(string input)

    {

        return Regex.Replace(input, @"(^\w)|(\s\w)", m => m.Value.ToUpper());

    }

}