Problem:
Score : 100 points

Problem Statement

You are given two integers a and b.
Determine if a+b=15 or a\times b=15 or neither holds.

Note that a+b=15 and a\times b=15 do not hold at the same time.

Constraints

1 \leq a,b \leq 15

All values in input are integers.

Input

Input is given from Standard Input in the following format:

a b

Output

If a+b=15, print +;
if a\times b=15, print *;
if neither holds, print x.

Sample Input 1

4 11

Sample Output 1

+

4+11=15.

Sample Input 2

3 5

Sample Output 2

*

3\times 5=15.

Sample Input 3

1 1

Sample Output 3

x

1+1=2 and 1\times 1=1, neither of which is 15.

Solution in Haskell (GHC 7.10.3) (judge verdict: Accepted)

iogetints :: IO [Int]
iogetints = do
  s <- getLine
  return $ map read $ words s

solve :: Int -> Int -> Char
solve a b
	| a + b == 15 = '+'
	| a * b == 15 = '*'
	| otherwise = 'x'

main :: IO ()
main = do 
	[a, b] <- iogetints
	putChar (solve a b)