U.S. Social Security number/phone number

using System;
using System.Text.RegularExpressions;

class Program
{
    static void Main(string[] args)
    {

         string ssNum = @"\d{3}-\d{2}-\d{4}"; 
    
         Console.WriteLine (Regex.IsMatch ("111-11-1111", ssNum));                  
    
         string phone = @"(?x) 
            ( \d{3}[-\s] | \(\d{3}\)\s? ) 
              \d{3}[-\s]? 
              \d{4}"; 
    
         Console.WriteLine (Regex.IsMatch ("111-111-1111",phone));     
         Console.WriteLine (Regex.IsMatch ("(111) 111-1111", phone));               
    
    }
}