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 C# (Mono 4.6.2.0) (judge verdict: Runtime Error)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
//using System.Threading.Tasks;

namespace A
{
    class Program
    {
        static void Main(string[] args)
        {
            long N = long.Parse(Console.ReadLine());
            long[] input = Console.ReadLine().Split(' ').Select((x) => long.Parse(x)).ToArray();
            int ans = 1;
            bool flag; //増加→true
           // bool first = false; //配列の最初
            if (input[0] < input[1]) flag = true;
            else flag = false;

            for(long i = 2; i < input.Length - 1; ++i)
            {
                if (flag)
                {
                    if (input[i - 1] > input[i])
                    {
                        
                        flag = !flag;
                        ++ans;
                        Console.WriteLine(i + "番目 " + ans + "個 flag=" + flag );
                    }
                }
                else
                {
                    if (input[i - 1] < input[i])
                    {
                        //first = true;
                        flag = !flag;
                        ++ans;
                        Console.WriteLine(i + "番目 " + ans + "個 flag=" + flag );
                    }
                }
            }
            Console.WriteLine(ans);
        }
    }
}