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)

main = do
  n <- words <$> getLine
  let l = read $ head n
  let op = head $ tail n
  let r = read $ last n
  putStrLn $ biop op l r
  
biop :: String -> Int -> Int -> String
biop o l r
  | o == "+" = show $ l + r
  | o == "-" = show $ subtract r l
  | otherwise = undefined