using System;
using System.Text.RegularExpressions;
using System.Collections.Generic;
 
public class Test
{
	public static void Main()
	{
		string pattern = @"^(?!0+$)(\(?([0-9]{3})\)?[-. ]?([0-9]{3})[-. ]?([0-9]{4}))$";
 
        var strings = new List<string>() {
            "4561237890",
            "1234",
            "0000000000"
            };
        foreach (var input in strings)
        {
            foreach (Match m in Regex.Matches(input, pattern))
            {
                Console.WriteLine(m.Value);
            }
        }
	}
}

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