using System;

public class Program

{

    public static void Main()

    {

        bool check = false;

        int score = 0;

        while ( check == false ) 

        { // meaning same as check == false

            try

            {

                check = true;

                Console.Write("Input student score : ");

/* int */       score = int.Parse(Console.ReadLine()); 

                while (score < 0 || score > 100)

                   {

                       Console.Write("Input student score, again : ");

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

                    }

            }

            catch (FormatException e) 

            {

                check = false;

                Console.WriteLine("You input wrong type");

            } 

       }

       Console.WriteLine("Your score is {0}", score);

    }

}