Problem:
Score: 500 points

Problem Statement

We have caught N sardines. The deliciousness and fragrantness of the i-th sardine is A_i and B_i, respectively.

We will choose one or more of these sardines and put them into a cooler. However, two sardines on bad terms cannot be chosen at the same time.

The i-th and j-th sardines (i \neq j) are on bad terms if and only if A_i \cdot A_j + B_i \cdot B_j = 0.

In how many ways can we choose the set of sardines to put into the cooler? Since the count can be enormous, print it modulo 1000000007.

Constraints

All values in input are integers.

1 \leq N \leq 2 \times 10^5

-10^{18} \leq A_i, B_i \leq 10^{18}

Input

Input is given from Standard Input in the following format:

N
A_1 B_1
:
A_N B_N

Output

Print the count modulo 1000000007.

Sample Input 1

3
1 2
-1 1
2 -1

Sample Output 1

5

There are five ways to choose the set of sardines, as follows:

The 1-st

The 1-st and 2-nd

The 2-nd

The 2-nd and 3-rd

The 3-rd

Sample Input 2

10
3 2
3 2
-1 1
2 -1
-3 -9
-8 12
7 7
8 1
8 2
8 4

Sample Output 2

479

Solution in Haskell (GHC 8.8.3) (judge verdict: Runtime Error)

{-# LANGUAGE TypeApplications #-}
module Main where
import qualified Data.ByteString.Char8         as BS
import qualified Data.ByteString.Lazy.Char8    as BSL
import qualified Data.ByteString.Builder       as BSB
import           Data.Char                      ( isSpace )
import           Data.List
import qualified Data.Vector                   as V
import qualified Data.Vector.Mutable           as VM
import qualified Data.Vector.Unboxed           as VU
import qualified Data.Vector.Unboxed.Mutable   as VUM
import qualified Data.Vector.Generic           as VG
import qualified Data.Vector.Generic.Mutable   as VGM
import           Data.Ratio

import           Data.Map.Strict            ( Map )
import qualified Data.Map.Strict           as Map

main :: IO ()
main = do
  n <- readLn @ Int
  abs <- V.replicateM n $ (\[x, y] -> (x, y)) . unfoldr (BS.readInt . BS.dropWhile isSpace) <$> BS.getLine
  let abs' = V.map f abs
  let h = Map.fromListWith (+) [ (x, 1) | x <- V.toList abs' ]
  print $ go h 1 - 1
 where
  go h ans
    | Map.null h = ans
    | otherwise = 
      let 
        ((r, c), h') = Map.deleteFindMin h
        r' = (-1) / r :: Ratio Int
      in case h' Map.!? r' of
        Nothing -> go h' (2^c * ans)
        Just c' -> go (Map.delete r' h') ((2^c-1 + 2^c'-1 + 1) * ans)

f :: (Int, Int) -> Ratio Int
f (a, b) = a % b