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 Python (3.4.3) (judge verdict: Accepted)


n = int(input())
a_ = list(map(int, input().split(' ')))
a = [-1]
i = 0
while  i < n:
    if a[-1] != a_[i]:
        a.append(a_[i])
    i += 1
a = a[1:]
n = len(a)

ret = 1

i = 0
while i < n-2:
    if (a[i] > a[i+1] and a[i+1] < a[i+2]) or (a[i] < a[i+1] and a[i+1] > a[i+2]):
        ret += 1
        i += 2
    else:
        i += 1
        
print(ret)