#include<bits/stdc++.h>

using namespace std;

int n,a[10005];
bool pd;//积水低洼地的条件是否达成 
int ans;

int main(){
	cin >> n;
	for(int i = 1;i <= n;i++){
		cin >> a[i];
	}
	for(int i = 2;i <= n;i++){
		if(a[i - 1] > a[i]){
			pd = 1;
		}
		if(a[i+1] > a[i]){
			if(pd == 1){
				ans++;
				pd = 0;
			}
		}
	}
	cout<<ans;
	return 0;
}