using System;

using System.Linq;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("How many people are in your class? ");

        oops:

        string net = Console.ReadLine();

        int classSize;

        if(int.TryParse(net, out classSize))

        {

        Console.WriteLine("Please input a correct number");

         goto oops;

        }

            else

            {   

        string[]students = new string[classSize];

        for(int i = 0; i < classSize; i++)

        {Console.WriteLine("Please enter person "+ (i+1));

            students[i] = Console.ReadLine();

             Console.Clear();

        }

        Array.Sort(students);

        Console.WriteLine("The people in your class in alphabetical order are: ");

        foreach(string name in students)

        {

            Console.Write(name + "  ");

        }  

    }

}

    }

​