The last statement won't run c#!

Question

Please help! I ran this program and entered all 3 inputs but the last writeline code wouldn't run and the program just exits itself! I have no idea because I follow the book exactly!

        string userName = "";
        int userAge = 0;
        int currentYear = 0;

        Console.Write("Please enter your name: ");
        userName = Console.ReadLine();
        Console.Write("Please enter your age: ");
        userAge = Convert.ToInt32(Console.ReadLine());
        Console.Write("Please enter the current year: ");
        currentYear = Convert.ToInt32(Console.ReadLine());

        Console.WriteLine("Hello World! My name is {0} and I am {1} years old. I was born in {2}.", userName, userAge, currentYear - userAge);

Answer 1

at the end of the code add:

Console.ReadLine();