using System;

​

public class Program

{

    public static void Main()

    {

        //Get a string from the user (this string represents a student’s major.)

        string strmajor;

        Console.WriteLine("Please type in your major");

        strmajor = Console.ReadLine();

        int int_score;

        //Get a number from a user (this number represents a student’s score.)

        string strscore;

        Console.WriteLine("Please type in your score");

        strscore = Console.ReadLine();

​

        //Validate whether the score is a whole number

        bool IsValidNumber = Int32.TryParse(strscore, out int_score);

        if (IsValidNumber == false)

        {

            Console.WriteLine("Please enter a valid number!");

            return;

        }

        else {

            Console.WriteLine("Score is a whole number.");

        }

        //Validate whether the score is between 0-100

        if (int_score >= 0 && int_score <= 100){

            Console.WriteLine("Score is valid.");

        }

        else {

            Console.WriteLine("Please enter a score between 0-100!");

        }

        //Use an if statement to determine the letter grade of the user based on score

        if (int_score >= 90) {

            Console.WriteLine("You get an A.");

        }

        else if (int_score >= 80 && int_score <= 89) {

            Console.WriteLine("You get a B.");

        }

        else if (int_score >= 70 && int_score <= 79) {

            Console.WriteLine("You get a C.");

        }

        else if (int_score >= 60 && int_score <=69) {

            Console.WriteLine("You get a D.");

        }

        else if(int_score < 60){

            Console.WriteLine("You get an F");

        }

        //If the score is greater than 90, check the student's major

        if (int_score >= 90 && strmajor == "Information Systems"){

            Console.WriteLine("Congratulations! You are one of the best students in IS.");

        }

        else if(int_score >= 90){

            Console.WriteLine("Congratulations! You are one of the best students.");

        }

    }

}

​

​