using System;
using System.Text.RegularExpressions;

public class Test
{
	public static void Main()
	{
		string s1 = "thisIsaString-A21";
		Console.WriteLine(Regex.IsMatch(s1, @"-A\d"));
		
		string s2 = "thisIsaString-AB21";
		Console.WriteLine(Regex.IsMatch(s2, @"-A\d"));
	}
}