#include<iostream>
int main()
{
    int n,sum=2;
    std::string s;
    std::cin>>n>>s;
    for(int i=0;i<s.length();i+=1)
    {
        if(s[i]=='S'&&i<n-1)sum+=1;
        else if(i+1<n-1)
        {
            sum+=1;
            i+=1;
        }
    }
    std::cout<<std::min(sum,n);
}

#include <bits/stdc++.h>
using namespace std;
int n;
string a;
int main()
{
    int sum = 2;
    cin >> n;
    cin >> a;
    for (int i =0;i < a.length();i++)
    {
        if (a[i] == 'S' && i < n-1)
        {
            sum++;
        }
        else if (i+1< n-1)
        {
            sum++;
            i++;
        }
    }
    cout << min(sum,n);
    return 0;
}

#include <iostream>
int main(){
    int n,sum=2;std::string a; std::cin>>n>>a;
    for(int i=0;i<a.length();i++){
        if(a[i]=='S'&&i<n-1)sum++;
        else if(i+1<n-1)sum++,i++;}
    std::cout<<std::min(sum,n); return 0;}