using System;
using System.Text.RegularExpressions;
public class Program {
public static void Main () {
Console.WriteLine(new Regex("^([✓✔]|🗸)$").IsMatch("🗸")); // => true
Console.WriteLine(new Regex("^[✓✔🗸]$").IsMatch("🗸")); // => false
Console.WriteLine(new Regex("[✓✔🗸]").IsMatch("🗸")); // => true (surrogate pair の片割れづつがマッチする)
}
