#include <bits/stdc++.h>
#define ll long long 
#define INF (ll)1e16
using namespace std;

const int MOD = 1e9 + 7;  // Removed "long long" after const int

int getCount(int x )
{
    int total =  0 ;

    while(x % 2 == 0 )
    {
        x /= 2 ; 
        total++ ; 
    }
    return total ; 
}

int main() {

    int t = 1; cin >> t;

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

    ll cnt  = 0  ; 

    if(s[0] != s[2 ] and s[1] != s[3])
    {
        cnt++ ; 
    }

    for(ll i = 1 ; i  < n - 1 ; i++)
    {
        if(s[i] != s[i-1] or s[i+1] != s[i+2])
        {
            cnt++ ; 
        }
    }
cout << cnt << endl ;
    }

    return 0;
}