#include <iostream>
#include <stdio.h>
#include <math.h>

using namespace std;


int main(){
       freopen("input.txt","r",stdin);
	   freopen("output.txt","w",stdout);
    
    int n=0,count=0,k=0;
    int a[1000]={0};
    cin>>n;
	   for(int i=0;i<n;i++){
           
           cin>>a[i];
       }
	   int rembFirst=0;
	   bool enterance=false;
       bool remember=true;
	   do{
           enterance=false;
           for(int i=1;i<n;i++){
               
               
               if(a[i]==a[i-1]){
                   
                   if(remember) {
                    rembFirst=i-1;
                    remember=false;
                   }
                   enterance=true;
                   count++;
                   
               }
               if(a[i]!=a[i-1] || i==(n-1)){
                   
                   if(count>=3){
                       for(int  z=rembFirst;z<n;++z){
                           a[z]=a[z+count];
                       }
                       k+=count;
                       n-=count;
                       count=1;
                       remember=true;
                       rembFirst=0;
                       break;
                   }
                   remember=true;
                   rembFirst=0;
                   count=1;
               }
               
               
           }
           
       }while(enterance);
    
    
    cout<<k;
    
    return 0;
}