#include <iostream>
#include <cstdio>
#include <iomanip>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <bitset>
#include <stack>
#include <utility>
#include <numeric>
#include <algorithm>
#include <functional>
#include <cctype>
#include <complex>
#include <string>
#include <sstream>
#include <fstream>
#include <cassert>
using namespace std;

//common
typedef int  i32;
typedef long long i64,ll;
typedef vector<int> vi; typedef pair<int,int> pii; typedef vector<pair<int,int> > vpii;
typedef long long ll; typedef vector<long long> vl; typedef pair<long long,long long> pll; typedef vector<pair<long long,long long> > vpll;
typedef vector<string> vs; typedef long double ld;

#define BR "\n"
#define ALL(c) (c).begin(),(c).end()
#define REP(i,n) for(int i=0;i<(int)(n);++i)
#define EACH(it,o) for(auto it = (o).begin(); it != (o).end(); ++it)
#define IN(l,v,r) ((l)<=(v) && (v)<(r))

//config
//#undef NDEBUG
//#define INF 1<<30
//#define EPS 1e-8
//const ll MOD =100000007;

//debug
#ifdef NDEBUG
#define DUMP(x)
#define DUMPLN(x)
#define DEBUG(x)
#define DEBUGLN(x)
#define LINE()
#define LINELN()
#define CHECK(exp,act)
#define STOP(e)
#else
#define DUMP(x)  cerr << #x << " = " << (x)
#define DUMPLN(x)  DUMP(x) <<endl
#define DEBUG(x) DUMP(x) << LINE() << " " << __FILE__
#define DEBUGLN(x) DEBUG(x)<<endl
#define LINE()    cerr<< " (L" << __LINE__ << ")"
#define LINELN()    LINE()<<endl
#define CHECK(exp,act)  if(exp!=act){DUMPLN(exp);DEBUGLN(act);}
#define STOP(e)  CHECK(e,true);if(!(e)) exit(1);
#endif

template<class T> inline string toString(const vector<T>& x) {
	stringstream ss;
	REP(i,x.size()){
		if(i!=0)ss<<" ";
		ss<< x[i];
	}
	return ss.str();
}

template<class T> inline string toString(const vector<vector<T> >& map) {
	stringstream ss;
	REP(i,map.size()){
		if(i!=0)ss<<BR;
		ss<< toString(map[i]);
	}
	return ss.str();
}
template<class K,class V>  string toString(map<K,V>& x) {
	string res;stringstream ss;
	for(auto& p:x)ss<< p.first<<":" << p.second<<" ";
	return ss.str();
}

string BITtoString(int bit){
    stringstream ss;
    while(bit!=0){ss<<(bit%2);bit/=2;}
    string res=ss.str();reverse(ALL(res));
    return res;
}

template<typename T,typename V> inline T mod(T v,V MOD){
	return (v%MOD+MOD)%MOD;
}

int INF=1<<28;
class Main{
public:
	void run(){
		//ofstream cout( "out2" );
		int T;cin >>T;
		REP(t,T){
			int N;cin >>N;
			string  s;cin >>s;

			vector<vector<int>> dp(N+1,vector<int>(3,INF));
			
			bool h1=s[0]=='Y';
			bool h2=s[2*N]=='Y';
			dp[0][0]=h2?3:(h1?1:0);dp[0][1]=h2?2:1;dp[0][2]=2;
			for(int pos=1;pos<=N;pos++){
				bool h1=(s[2*pos-1]=='Y') || (2*pos<2*N && (s[2*pos]=='Y') );
				bool h2=(s[2*N+2*pos-1]=='Y') || (2*N+2*pos<4*N && (s[2*N+2*pos]=='Y'));

				dp[pos][0]=min(dp[pos][0],1+dp[pos-1][0]+(h2?3:(h1?1:0)));
				dp[pos][0]=min(dp[pos][0],1+dp[pos-1][1]+(h2?2:1));
				dp[pos][0]=min(dp[pos][0],1+dp[pos-1][2]+2);
				
				dp[pos][1]=min(dp[pos][1],1+dp[pos-1][0]+(h2?2:1));
				dp[pos][1]=min(dp[pos][1],1+dp[pos-1][1]+((h1&&h2)?2:((h1||h2)?1:0)));
				dp[pos][1]=min(dp[pos][1],1+dp[pos-1][2]+(h1?2:1));
				
				dp[pos][2]=min(dp[pos][2],1+dp[pos-1][0]+2);
				dp[pos][2]=min(dp[pos][2],1+dp[pos-1][1]+(h1?2:1));
				dp[pos][2]=min(dp[pos][2],1+dp[pos-1][2]+(h1?3:(h2?1:0)));
			}
		//	DUMP(toString(dp));
			cout<<dp[N][0]<<endl;
		}
	}
};
 int main(){
 	Main().run();
 	//Main().main();
 	return 0;
 }

Measured memory_bytes: 1812