using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text.RegularExpressions;
 
public class Test
{
	public static void Main()
	{
    	var line = @"0001 Lorem ipsum dolor sit\011 tortor neque\ 0111\interdum magn";
    	var pattern = @"[^\\]+\\[^\\]+$";
    	var result = Regex.Match(line, pattern, RegexOptions.RightToLeft);
        if (result.Success)
        	Console.WriteLine(result.Value);
	}
}

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