题号P1317

#include <bits/stdc++.h>
using namespace std;
int main(){
  int n,a[10005]={0},s=0,b=0;
  cin>>n;
  for(int i=1;i<=n;i+=0){
     cin>>a[i];
     if(a[i]!=a[i-1]){
         i++;
         b++;
     }
  }
   for(int i=3;i<=b;i++){
       if(a[i]>a[i-1] && a[i-2]>a[i-1]){
          s+=1;
       }
   }
   cout<<s;
   return 0; 
}