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 JavaScript (node.js v5.12) (judge verdict: Accepted)

var input = require("fs").readFileSync("/dev/stdin", "utf8");

input = input.split('\n')

var seq = input[1].split(' ').map(x => parseInt(x))

var pause = 1;
var diffSign = 0;

for (var i = 1; i < seq.length; i++) {
    var nowSign = Math.sign(seq[i - 1] - seq[i])
    if (diffSign * nowSign < 0) {
        pause++;
        diffSign = 0;
    } else if (diffSign === 0) {
        diffSign = nowSign;
    }
}

console.log(pause)