Problem:
Score : 100 points

Problem Statement

Joisino wants to evaluate the formula "A op B".
Here, A and B are integers, and the binary operator op is either + or -.
Your task is to evaluate the formula instead of her.

Constraints

1≦A,B≦10^9

op is either + or -.

Input

The input is given from Standard Input in the following format:

A op B

Output

Evaluate the formula and print the result.

Sample Input 1

1 + 2

Sample Output 1

3

Since 1 + 2 = 3, the output should be 3.

Sample Input 2

5 - 7

Sample Output 2

-2

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

import Control.Applicative

main :: IO ()
main = do
  [a,op,b] <- words <$> getLine
  print $ solve2 a op b

solve2 :: String -> String -> String -> Int
solve2 a op b
  | op == "+" = (read a :: Int) + (read b :: Int)
  | op == "-" = (read a :: Int) - (read b :: Int)