Problem:
Score : 300 points

Problem Statement

You are given an array A of length N.
Your task is to divide it into several contiguous subarrays.
Here, all subarrays obtained must be sorted in either non-decreasing or non-increasing order.
At least how many subarrays do you need to divide A into?

Constraints

1 \leq N \leq 10^5

1 \leq A_i \leq 10^9

Each A_i is an integer.

Input

Input is given from Standard Input in the following format:

N
A_1 A_2 ... A_N

Output

Print the minimum possible number of subarrays after division of A.

Sample Input 1

6
1 2 3 2 2 1

Sample Output 1

2

One optimal solution is to divide the array into [1,2,3] and [2,2,1].

Sample Input 2

9
1 2 1 2 1 2 1 2 1

Sample Output 2

5

Sample Input 3

7
1 2 3 2 1 999999999 1000000000

Sample Output 3

3

Solution in Haskell (GHC 7.10.3) (judge verdict: Wrong Answer)

import qualified Data.ByteString.Char8 as B
import Data.List

main = do
  _ <- getLine
  as <- map (maybe undefined fst . B.readInt) . B.words <$> B.getLine
  print (sarray as)

sarray as = sum $ unfoldr cut $ groupBy (\x y -> x==y || x==0 || y==0) ds
  where
    ds = map signum $ zipWith (-) (tail as) as

cut [] = Nothing
cut [g] = Just (1, [])
cut [g,[n]] = Just (2, [])
cut (g:[n]:gs) = Just (1, gs)
cut (_:_:gs) = Just (2,gs)