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
/*
    Problem URL : http://agc013.contest.atcoder.jp/tasks/agc013_a

    Score  :
    Result :
    Time   : ms
    Memory : KB
 */

fscanf(STDIN, "%d", $N);
$A = explode(" ", trim(fgets(STDIN)));

$prev = PHP_INT_MAX;

$ans = 0;

for ($i = 0; $i < $N - 1; $i++) {
    // echo "* {$A[$i+1]} {$A[$i]}\n"; 
    if ($A[$i+1] == $A[$i]) {
        $flg = 0;
    } elseif ($A[$i+1] > $A[$i]) {
        $flg = 1;
    } else {
        $flg = -1;
    }

    if ($flg != 0) {
        if ($flg != $prev) {
            $ans++;
        }
        $prev = $flg;
    }
    // echo "{$prev} {$flg} {$ans} " . PHP_EOL;
}

echo $ans . PHP_EOL;