#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#define rep(i,j,k) for(int i=(j);i<=(k);i++)
#define per(i,j,k) for(int i=(j);i>=(k);i--)
#define uint unsigned int
#define ll long long
#define ull unsigned long long
#define db double
#define ldb long double
#define pii pair<int,int>
#define pll pair<ll,ll>
#define mkp make_pair
#define eb emplace_back
#define SZ(S) (int)S.size()
//#define mod 998244353
//#define mod 1000000007
#define inf 0x3f3f3f3f
#define linf 0x3f3f3f3f3f3f3f3f
using namespace std;

template <class T>
void chkmax(T &x,T y){
	if(x < y) x = y;
}

template <class T>
void chkmin(T &x,T y){
	if(x > y) x = y;
}

inline int popcnt(int x){
	return __builtin_popcount(x);
}

inline int ctz(int x){
	return __builtin_ctz(x);
}


/*ll power(ll p,int k = mod - 2){
	ll ans = 1;
	while(k){
		if(k % 2 == 1) ans = ans * p % mod;
		p = p * p % mod;
		k /= 2;	
	}
	return ans;
}*/
int T,n;
char s[200005];
int a[200005];

int tr[4][2],val[4][2];
int dp[4][4],ndp[4][4];
void trans(){
	rep(p,0,2){
		rep(q,0,3){
			chkmax(dp[p + 1][tr[q][0]],dp[p][q] + val[q][0] - p);
			chkmax(dp[p + 1][tr[q][1]],dp[p][q] + val[q][1] - p);
		}
	}
}

void dbg(){
	rep(p,0,3){
		rep(q,0,3) printf("(p=%d q=%d dp=%d)\n",p,q,dp[p][q]);
	}
}

void solve(){
	scanf("%d",&n);
	scanf("%s",s + 1);
	rep(i,1,n){
		if(s[i] == 'C') a[i] = 0;
		else a[i] = 1;
	}

	memset(dp,0xcf,sizeof(dp));
	dp[0][0] = 0;
	trans();
	rep(i,1,n){
		memset(ndp,0xcf,sizeof(ndp));
		rep(p,0,3){
			rep(q,0,3){
				chkmax(ndp[p][tr[q][a[i]]],dp[p][q] + val[q][a[i]]);
			}
		}
		rep(p,0,3){
			rep(q,0,3) dp[p][q] = ndp[p][q];
		}
		trans();
//		dbg();
	}
	int answer = -inf;
	rep(p,0,3){
		rep(q,0,3) chkmax(answer,dp[p][q]);
	}
	printf("%d\n",answer);
}

int main(){
//	freopen("test.in","r",stdin);
	tr[0][0] = 1;tr[0][1] = 0;
	tr[1][0] = 2;tr[1][1] = 0;
	tr[2][0] = 2;tr[2][1] = 3;
	tr[3][0] = 1;tr[3][1] = 0;val[3][0] = 1;
	scanf("%d",&T);
	while(T--) solve();
	return 0;
}