Tutorial: Averaging Program

package tutorial;

import java.util.Scanner;

class Tutorial {
    public static void main(String args[]){
        Scanner input = new Scanner(System.in);
        Scanner answer = new Scanner(System.in);

        int total = 0;
        int gradeInput;
        int average = 0;
        int counter = 1;
        int numberGrades;
        String rerunAnswer;

        System.out.println("How many grades would you like to average? (whole number)");
        numberGrades = input.nextInt();
        if(numberGrades > 0){
            while(counter < numberGrades + 1){
                System.out.println("Please enter grade " + counter);
                gradeInput = input.nextInt();
                total += gradeInput;
                counter++;
            }
            average = total / numberGrades;
            System.out.println("The average for the " + numberGrades + " grades you entered is " + average+"\n");
            System.out.println("Would you like to average more grades? (Yes or No)");
            rerunAnswer = answer.nextLine();
            rerunAnswer = rerunAnswer.toLowerCase();
            if(rerunAnswer.equals("yes")){
                System.out.println("\nRestarting program.");
                main(args);
            } else {
                System.out.println("Exiting program.");
            }
        } else {
            System.out.println("Error: Please enter a number greater than zero.\n Restarting program.\n");
            main(args);
        }
    }
}