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 Haskell (GHC 7.10.3) (judge verdict: Accepted)

import Control.Monad
import Text.Printf

main :: IO ()
main = do
    [a, b] <- getInts
    print $ if b `mod` a == 0 then a + b else b - a

getLines :: Int -> IO [String]
getLines n = replicateM n getLine

getLinesInt :: Int -> IO [Int]
getLinesInt n = fmap read <$> getLines n

getInts :: IO [Int]
getInts = map (read :: String -> Int) . words <$> getLine

getDoubles :: IO [Double]
getDoubles = map (read :: String -> Double) . words <$> getLine