import java.util.Scanner;

public class Multicalculator {
    public static void main(String[] args) {
        String yourNumbers = enterNum();
        int numberOne = stringToInteger(yourNumbers);
        for (numberOne = 0; ; numberOne--){
            System.out.println("Please, enter a number");
        }
    }

    public static String enterNum() {
        Scanner scanner = new Scanner(System.in);
        System.out.println("How many numbers would you like to enter?");
        String yourNumbers = scanner.nextLine();
        boolean isItNum = checkString(yourNumbers);
        while (!isItNum) {
            System.out.println("Please, enter a number:");
            yourNumbers = scanner.nextLine();
            isItNum = checkString(yourNumbers);
        }
        return yourNumbers;
    }

    public static int stringToInteger(String numbers) {
        return Integer.parseInt(numbers);
    }

    public static boolean checkString(String string) {
        try {
            Integer.parseInt(string);
            return true;
        } catch (IllegalArgumentException e) {
            return false;
        }
    }

}