I can't enter in the case 2 of the switch statement and I don't know why. If I remove the do while loop the code runs perfectly. It's about something with the memory of the structure array? Here is the code:

```
class Notebook {

        struct Student
        {
            public String id;
            public String name;
            public void showInfo(Student x) {
                Console.WriteLine("\t ID: " + x.id);
                Console.WriteLine("\t Name: " + x.name);
            }

        }
        static void Main(string[] args){

            bool display = true;

            int studentNum = int.Parse(Console.ReadLine());

            Student[] students = new Student[studentNum];

            do {

                Console.Clear();
                Console.WriteLine("1.- Insert register");
                Console.WriteLine("2.- Show register");
                Console.WriteLine("3.- Exit");

                String opc = Console.ReadLine();

                switch (opc) {

                    case "1":
                        Console.Clear();
                        for(int i = 0; i < students.Length; ++i){
                            Console.WriteLine("Name of the student " + (i+1));
                            students[i].name = Console.ReadLine();
                            Console.WriteLine("ID of the student " + (i+1));
                            students[i].id = Console.ReadLine();
                        }
                        break;

                    case "2":
                        Console.Clear();
                        for(int i = 0; i < students.Length; ++i){
                            students[i].showInfo(students[i]);
                        }
                        break;

                    case "3":
                        Console.Clear();
                        Console.WriteLine("bye");
                        display = false;
                        break;

                }

            }while(display);

        }
    }

```

I think that is "something" in the memory of opc string that avoids the case 2.