using System;
using System.Text;

public static class StringExtensions
{
    public static string Repeat(this string input, int count)
    {
        if (input == null)
        {
            return null;
        }

        var sb = new StringBuilder();

        for (var repeat = 0; repeat < count; repeat++)
        {
            sb.Append(input);
        }

        return sb.ToString();
    }
}

public class Test
{
	public static void Main()
	{
		Console.Out.WriteLine("Hello".Repeat(3));
	}
}