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 PHP7 (7.0.15) (judge verdict: Wrong Answer)

<?php
$N = trim(fgets(STDIN));
$A = explode(" ", trim(fgets(STDIN)));

$up = $A[0] < $A[1];
$count = 1;

for ($i = 1; $i < $N - 1; $i++) {
    if ($up && $A[$i] > $A[$i + 1]) {
        $count++;

        if (isset($A[$i + 2])) {
            $up = $A[$i + 1] < $A[$i + 2];
        }
    }

    if (!$up && $A[$i] < $A[$i + 1]) {
        $count++;

        if (isset($A[$i + 2])) {
            $up = $A[$i + 1] < $A[$i + 2];
        }
    }
}

echo $count;