#include <bits/stdc++.h>
using namespace std;

int main(){
	int n,a[110],i,c = 0;
	cin>>n;
	for(i = 0;i < n;i++){
		cin>>a[i];
	} 
	
	//找浪尖数
	for(i = 1;i < n - 1;i++){
		if(a[i] > a[i-1] && a[i] > a[i+1]){
			c++;
		}
	} 
	  
	cout<<c<<endl;  
    return 0;
}

/**************************************************************
	Problem: 1401
	User: admin
	Language: C++
	Result: Accepted
	Time:21 ms
	Memory:2072 kb
****************************************************************/