package com.company;

import java.util.Scanner;

public class Main {
    static int enter(int max, int min) {
        Scanner scanner = new Scanner(System.in);
        int temp = 0;
        boolean iscorrect = true;
        do {
            try {
                temp = scanner.nextInt();
                if ((temp > min) && (temp < max)) {
                    iscorrect = false;
                } else {
                    System.out.println("This is a mistake. Please enter again!");
                }
            } catch (Exception e) {
                scanner.nextLine();
                System.out.println("This is a mistake. Please enter again!");
                iscorrect = true;
            }
        }
        while (iscorrect);
        return temp;
    }

    static int transfer(int j, int n, int num) {
        int res = 0;
        int temp = 1;
        for (int i = j; i < n - 1; i++) {
            temp = temp * 10;
        }
        res = res + (num * temp);
        return res;
    }

    static int subtraction(int j, int n, int num) {
        int res = 0;
        int temp = 1;
        temp = temp * 10;
        res = res + (num % temp);
        return res;
    }

    public static void main(String[] args) {
        int n;
        int num1 = 0;
        int num2 = 0;
        int[] numb1 = new int[10];
        int[] numb2 = new int[10];
        int[] res = new int[10];
        System.out.println("Enter the number of numb (n > 0 and n < 10)");
        n = enter(10, 0);
        for (int i = 0; i < n; i++) {
            System.out.println("Enter the " + (i + 1) + " digit of the first number(digit > 0 and digit < 10)");
            numb1[i] = enter(10, -1);
        }
        for (int i = 0; i < n; i++) {
            System.out.println("Enter the " + (i + 1) + " digit of the second number(digit > 0 and digit < 10)");
            numb2[i] = enter(10, -1);
        }
        for (int i = n - 1; i > -1; i--) {
            num1 = num1 + transfer(i, n, numb1[i]);
            num2 = num2 + transfer(i, n, numb2[i]);
        }
        num1 = num1 - num2;
        if (num1 < 0) {
            num1 = (Math.abs(num1));
            for (int i = n - 1; i > -1; i--) {
                res[i] = subtraction(i, n, num1);
                num1 = num1 / 10;
            }
            res[0] = res[0] * (-1);
        } else {
            for (int i = n - 1; i > -1; i--) {
                res[i] = subtraction(i, n, num1);
                num1 = num1 / 10;
            }
        }
        for (int i = 0; i < n; i++) {
            System.out.print(res[i]);
        }
    }
}