Problem:
Score : 100 points

Problem Statement

You are given positive integers A and B.

If A is a divisor of B, print A + B; otherwise, print B - A.

Constraints

All values in input are integers.

1 \leq A \leq B \leq 20

Input

Input is given from Standard Input in the following format:

A B

Output

If A is a divisor of B, print A + B; otherwise, print B - A.

Sample Input 1

4 12

Sample Output 1

16

As 4 is a divisor of 12, 4 + 12 = 16 should be printed.

Sample Input 2

8 20

Sample Output 2

12

Sample Input 3

1 1

Sample Output 3

2

1 is a divisor of 1.

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		int N = scanner.nextInt();
		int M = scanner.nextInt();
		scanner.nextLine();
		List<Integer> alList = new ArrayList<>();
		for (int i = 1; i <= M; i++) {
			alList.add(i);
		}

		while (scanner.hasNextLine()) {
			String string = scanner.nextLine();
			String[] s = string.split(" ");
			List<String> kIntegers = new ArrayList<>();
			for (String k : s) {
				kIntegers.add(k);
			}
			List<Integer> nothing = new ArrayList<>();
			for (int i = 1; i <= M; i++) {
				if (!kIntegers.contains(String.valueOf(i))) {
					nothing.add(i);
				}
			}

			alList.removeAll(nothing);
		}

		System.out.println(alList.size() - 1);
	}
}