C

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

int main() {
    int t;
    cin>>t;

    while(t--){
        int n;
        string s;
        cin>>n>>s;

        int ans = n-2;
        int chk = 0;

        for(int i=0; i<n-2; i++)
        {
            if(i<n-3 && (s[i]==s[i+1] && s[i+1]!=s[i+2] && s[i+1]==s[i+3]))     **#*
                ans--;

            if(s[i]==s[i+1] && s[i]==s[i+2])            ***
            {
                ans--;
                chk = 1;
            }
        }

        cout<<ans + chk<<"\n";
    }
}