#include<bits/stdc++.h>
using namespace std;
int main()
{
	int n,i,j,a[10],s=0,d;
	cin>>n;
	for(i=0;i<n;i++){
		cin>>a[i];
	}
	if(a[1]>a[0]){
		d=0;
	}else{
		d=1;
	}
	for(i=1;i<n;i++){
		if(d=0){
			if(a[i-1]>a[i]){
				d=1;
				s++;
			}
		}else{
			if(a[i-1]<a[i]){
				d=0;
				s++;
			}
		}
	}
	cout<<s;
	return 0;
}
/**************************************************************
	Problem: 1173
	User: zzz
	Language: C++
	Result: Accepted
	Time:6 ms
	Memory:2072 kb
****************************************************************/