Problem:
Score : 100 points

Problem Statement

You are given two positive integers a and b.
Let x be the average of a and b.
Print x rounded up to the nearest integer.

Constraints

a and b are integers.

1 \leq a, b \leq 100

Input

Input is given from Standard Input in the following format:

a b

Output

Print x rounded up to the nearest integer.

Sample Input 1

1 3

Sample Output 1

2

The average of 1 and 3 is 2.0, and it will be rounded up to the nearest integer, 2.

Sample Input 2

7 4

Sample Output 2

6

The average of 7 and 4 is 5.5, and it will be rounded up to the nearest integer, 6.

Sample Input 3

5 5

Sample Output 3

5

Solution in Haskell (GHC 7.10.3) (judge verdict: Runtime Error)

main = do
  s <- getLine
  [x, y] <- map read . words <$> getLine
  putStr $ solve s x y

solve s x y = judge $ move x y s

move x y [] = [(0, 0, x, y)]
move x y (c:cs) = move x y cs >>= step  c

step 'F' (x0, y0, x1, y1) = [(x0 + 1, y0, x1, y1)]
step 'T' (x0, y0, x1, y1) = [(x0, y0, -y1, x0), (x0, y0, y1, -x0)]

judge zs
  | any goal zs = "Yes"
  | otherwise = "No"

goal (x0, y0, x1, y1) = (x0, y0) == (x1, y1)