using System;

public class Program

{

    public static void Main()

    {

        int grade, sum=0, count=0 ,ilay=0;

        double avg;

        for(int i=1;i<=38;i++)

        {

            Console.WriteLine("enter grade");

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

            while (grade!= -999)

            {

                sum=sum+grade;

                count++;

                Console.WriteLine("enter grade");

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

            }

            avg=(double)sum/count;

            if(avg>90)

                ilay++;

            sum=0;

            count=0;

            Console.WriteLine(avg);

        }

        Console.WriteLine("there are "+ilay+" best student");

    }

}