Problem:
Problem Statement

You are given two integers a and b (a≤b). Determine if the product of the integers a, a+1, …, b is positive, negative or zero.

Constraints

a and b are integers.

-10^9≤a≤b≤10^9

Partial Score

In test cases worth 100 points, -10≤a≤b≤10.

Input

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

a b

Output

If the product is positive, print Positive. If it is negative, print Negative. If it is zero, print Zero.

Sample Input 1

1 3

Sample Output 1

Positive

1×2×3=6 is positive.

Sample Input 2

-3 -1

Sample Output 2

Negative

(-3)×(-2)×(-1)=-6 is negative.

Sample Input 3

-1 1

Sample Output 3

Zero

(-1)×0×1=0.

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

import Control.Applicative
import Control.Monad
import Data.List

main :: IO ()
main = do
    [a, b] <- fmap read . words <$> getLine :: IO [Int]
    let f c d
            | c >  0           = 1
            | c <= 0 && 0 <= d = 0
            | odd n            = -1
            | otherwise        = 1
          where
            n = d - c + 1
    case f a b of
        0 -> putStrLn "Zero"
        1 -> putStrLn "Positive"
        (-1) -> putStrLn "Negative"