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

#define debug(...)   printf( __VA_ARGS__ )
//#define debug(...)   /****nothing****/

#define ll long long
#define ull unsigned long long
#define pb push_back
#define mem(arr,val)    memset(arr,val,sizeof(arr))
#define mp make_pair
#define pii pair<int,int>
#define F first
#define S second
#define sz(x) (int)(x).size()
#define nopos string::npos
#define fr(i,a,b) for(i=a;i<=b;i++)
#define frn(i,a,b) for(i=a;i>=b;i--)
int n,ar[1234],i,j,cnt;
int lft[1234],indx[1234];

int main()
{
    //freopen("d://i.txt","r",stdin);
    //freopen("d://o.txt","w",stdout);
    while(cin>>n)
    {
        cnt=0;

        fr(i,1,n)
         scanf("%d",ar+i) , indx[ar[i]]=0;

        fr(i,1,n)
         lft[i]=indx[ar[i]] , indx[ar[i]]=i;

        int up=0,dwn=0,disturb=0,p1,p2,mid;
        ll ans=0;

        fr(i,1,n-2)
         {
             if(ar[i]>ar[i+1] && ar[i+1]>ar[i+2])
             {
                 dwn=3;
                 p1=i;

                 i+=3;
                 while(i<=n && ar[i]<ar[i-1])
                    dwn++ , i++;

                 p2=i-1;

                 up=1;
                 mid=10000007;
                 while(i<=n&&ar[i]>ar[i-1])
                   {
                       if(mid==10000007 && lft[i]>=p1&&lft[i]<=p2)
                        mid=1 , j=i;

                       up++ , i++;
                   }

                 if(mid==1 && up>1)
                    {
                        if(j!=i-1)
                        mid=up+dwn-4-1;
                        else
                        mid=up+dwn-3-1;
                    }

                 ans+=min(max(up-2,0)+ max(dwn-2,0) , mid);

                 if(up==1)
                    i-=1;
                 else
                   i-=2;
             }
             else if(ar[i]<ar[i+1] && ar[i+1]<ar[i+2])
             {
                 up=3;
                 p1=i;
                 i+=3;

                 while(i<=n && ar[i]>ar[i-1])
                    up++ , i++;

                 p2=i-1;

                 mid=10000007;
                 dwn=1;

                 while(i<=n&&ar[i]<ar[i-1])
                 {
                     if(mid==10000007 && lft[i]>=p1&&lft[i]<=p2)
                        j=i , mid=1;

                     dwn++ , i++;
                 }

                 if(mid==1 && dwn>1)
                    {
                        if(j!=i-1)
                        mid=up+dwn-4-1;
                        else
                            mid=up+dwn-3-1;
                    }

                 ans+=min(max(dwn-2,0)+max(up-2,0) , mid);

                 if(dwn==1)
                    i--;
                 else
                   i-=2;
             }

         }

        cout<<ans<<'\n';
    }



    return 0;
}