using System;
using System.Text.RegularExpressions;
 
public class RegexTest
{
	private static void TestInputPattern(string input, string pattern)
	{
		Console.WriteLine("Input: {0}, Pattern: {1}", input, pattern);
		Console.WriteLine("IsMatch: {0}", Regex.IsMatch(input, pattern));	
	}
 
	public static void Main()
	{
		string input = "this potato";
		string groupedPattern = "^(?:this|that)$";
		string ungroupedPattern = "^this|that$";
		TestInputPattern(input, groupedPattern);
		TestInputPattern(input, ungroupedPattern);
	}
}

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