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 Rust (1.15.1) (judge verdict: Accepted)

use std::io;
use std::str::FromStr;

fn main() {
    let mut buf = String::new();
    io::stdin().read_line(&mut buf).ok();

    let mut buf = buf.split_whitespace().map(|n| usize::from_str(n).unwrap());
    let (a, b) = (buf.next().unwrap(), buf.next().unwrap());

    let ans;
    if b % a == 0 {
        ans = a + b;
    } else {
        ans = b - a;
    }

    println!("{}", ans);
}