#include <bits/stdc++.h>
using namespace std;
#define print(l) for(auto i:l) cout<<i<<" ";cout<<endl;
#define input(t,l,n) vector<t>l(n);for(int i = 0;i<n;i++)cin>>l[i];
#define int long long
#define pb push_back
#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update> 
#define all(l) l.begin(),l.end()
#define pii pair<int,int>
#define fi first
#define se second
const int M = 1e9+7;
const int inf = 1e18;
int bp(int x, int y, int p){
    int res = 1;
    x = x % p;
    while (y > 0) {
 
        if (y & 1)
            res = (res * x) % p;
        y = y >> 1;
        x = (x * x) % p;
    }
    return res;
}
 
int MI(int n, int p){
    return bp(n, p - 2, p);
}
int mul(int x,int y, int p){
    return x * 1ull * y % p;
}
int di(int x,int y, int p){
    return mul(x, MI(y, p), p);
}
int n , m , k , q;
void solve(int testcase_number){
    cin>>n;
    string s,a;
    cin>>s;
    vector<string>com;
    char ii = s[0];
    int i =0 ;
    while(i<n){
    	while(s[i] == ii){
    		a+=s[i];
    		i++;
    	}
    	com.pb(a);
    	ii = s[i];
    	a = "";
    }
    string m1,m2;
    for(auto i:com){
    	int c =0 ;
    	int rg = min(2ll,(int)i.size());
    	if(i.size()<=2){
    		rg = 1;
    	}
    	for(int j = 0;j<rg;j++){
    		m1+=i[0];
    		c++;
    	}
    	while(c<i.size()){
    		m2+=i[0];
    		c++;
    	}
    	
    }
    char k = m1[0];
    m1 = k+m1;
    m1 = k+m1;
    k = m2[0];
    m2 = k+m2;
    m2 = k+m2;
    // string tp = to_string(m1[0]+m1[0]+m1);
    // cout<<m1<<endl;
    int ans = 0;
    for(int i = 2;i<m1.size();i++){
    	if(m1[i] == m1[i-1] and m1[i-2] == m1[i-1]){
    		ans++;
    	}
    	else if(m1[i]!= m1[i-1] and m1[i-1]!= m1[i-2] and m1[i-2] != m1[i]){
    		ans+=3;
    	}
    	else{
    		ans+=2;
    	}
    }
    m1 = m2;
    for(int i = 2;i<m1.size();i++){
    	if(m1[i] == m1[i-1] and m1[i-2] == m1[i-1]){
    		ans++;
    	}
    	else if(m1[i]!= m1[i-1] and m1[i-1]!= m1[i-2] and m1[i-2] != m1[i]){
    		ans+=3;
    	}
    	else{
    		ans+=2;
    	}
    }
    cout<<ans<<endl;
}
signed main(){
    // ios::sync_with_stdio(0);//DO NOT USE IN INTERACTIVE
    // cin.tie(0), cout.tie(0);
    // cout << fixed<<setprecision(9);
    int t = 1;
    // cin>>t;
    for(int i = 1;i<=t;i++){
        solve(i);
    }
}
| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... |