using System;

using System.Text.RegularExpressions;

public class Program

{

    public static void Main()

    {

        string s = "05 AA 06 15 14";

        var pattern1 = "05 AA";

        var pattern2 = "06 15";

        var pattern3 = "AA .. 15";

        var pattern4 = "15 14";

        var posP1 = Regex.Match(s, pattern1) is { Success: true } m1 ? m1.Index : -1;

        var posP2 = Regex.Match(s, pattern2) is { Success: true } m2 ? m2.Index : -1;

        var posP3 = Regex.Match(s, pattern3) is { Success: true } m3 ? m3.Index : -1;

        var posP4 = Regex.Match(s, pattern4) is { Success: true } m4 ? m4.Index : -1;

        Console.WriteLine(posP1);

        Console.WriteLine(posP2);

        Console.WriteLine(posP3);

        Console.WriteLine(posP4);

    }

}