Teacher code

// Teacher code program

using System;

class Submission
{
    // -------------------------
    // Subprograms
    // -------------------------
    static string tcode(string teacher)
    {
        string[] letters = new string[2];
        letters[0] = teacher.Substring(0, 1);
        int space = teacher.IndexOf(" ");
        letters[1] = teacher.Substring(space + 1, 2);
        string teacher_code = string.Join("", letters);
        teacher_code = teacher_code.ToUpper();
        return teacher_code;
    }

    // -------------------------
    // Main program
    // -------------------------
    public static void Main(string[] args)
    {
        Console.WriteLine("Enter the name of the teacher: ");
        string teacher = Console.ReadLine();
        string teacher_code = tcode(teacher);
        Console.WriteLine(teacher_code);
    }

}