using System;
using System.Linq;
using System.Text.RegularExpressions;
public class Test
{
	public static void Main()
	{
		const string stringToTest = "Am Rusch";
		const string patternToMatch = @"\bRusch*";
		Console.WriteLine(Regex.Split(stringToTest,@"[^\w\p{M}]+")
					.Where(m => !string.IsNullOrEmpty(m))
					.ToList()
					.FindIndex(p => Regex.IsMatch(p,patternToMatch))
		);
	}
}