using System;
using System.Text.RegularExpressions;
 
public class Test
{
	public static void Main()
	{
		string test = "This string has 1000, 2000, 3000, 4000 numbers as 1 or 2 or 3";
		string pattern = @"\d+";
		// Match match = Regex.Match(test, pattern);
		// while(match.Success){
		// 	Console.WriteLine(match.Value);
		// 	match = match.NextMatch();
		// }
		test = "42 is lucky number";
		Console.WriteLine(Regex.IsMatch(test, pattern));
		test = "4245";
		Console.WriteLine(Regex.IsMatch(test, @"^\d$"));
	}
}

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