#include <bits/stdc++.h>

#define FOR(i,a,b) for(int i= (a); i<((int)b); ++i)
#define RFOR(i,a) for(int i=(a); i >= 0; --i)
#define FOE(i,a) for(auto i : a)
#define ALL(c) (c).begin(), (c).end()
#define RALL(c) (c).rbegin(), (c).rend()
#define DUMP(x)  cerr << #x << " = " << (x) << endl;
#define SUM(x) std::accumulate(ALL(x), 0LL)
#define MIN(v) *std::min_element(v.begin(), v.end())
#define MAX(v) *std::max_element(v.begin(), v.end())
#define EXIST(v,x) (std::find(v.begin(), v.end(), x) != v.end())
#define BIT_ON(bit, i) (bit & (1LL << i))

typedef long long LL;
template<typename T> using V = std::vector<T>;
template<typename T> using VV = std::vector<std::vector<T>>;
template<typename T> using VVV = std::vector<std::vector<std::vector<T>>>;
template<typename T> using VVVV = std::vector<std::vector<std::vector<std::vector<T>>>>;

template<class T> inline T ceil(T a, T b) { return (a + b - 1) / b; }
template<class T> inline void print(T x) { std::cout << x << std::endl; }
template<class T> inline void print_vec(const std::vector<T> &v) { for (int i = 0; i < v.size(); ++i) {  if (i != 0) {std::cout << " ";} std::cout << v[i];} std::cout << "\n"; }
template<class T> inline bool inside(T y, T x, T H, T W) {return 0 <= y and y < H and 0 <= x and x < W; }
template<class T> inline double euclidean_distance(T y1, T x1, T y2, T x2) { return sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2)); }
template<class T> inline double manhattan_distance(T y1, T x1, T y2, T x2) { return abs(x1 - x2) + abs(y1 - y2); }
template<typename T> T &chmin(T &a, const T &b) { return a = std::min(a, b); }
template<typename T> T &chmax(T &a, const T &b) { return a = std::max(a, b); }
template<class T> inline std::vector<T> unique(std::vector<T> v) {
    sort(v.begin(), v.end());
    v.erase(unique(v.begin(), v.end()), v.end());
    return v;
}
// 初項s, 交差dのn個の数列の和
long long sum_of_arithmetic_progression(long long s, long long d, long long n) {
    return n * (2 * s + (n - 1) * d) / 2;
}

const int INF = 1 << 30;
const double EPS = 1e-9;
const std::string YES = "YES", Yes = "Yes", NO = "NO", No = "No";
const std::vector<int> dy4 = {0, -1, 0, 1}, dx4 = {1, 0, -1, 0};
const std::vector<int> dy8 = { 0, -1, 0, 1, 1, -1, -1, 1 }, dx8 = { 1, 0, -1, 0, 1, 1, -1, -1 };

using namespace std;

int solve(int N, string S) {
    VV<int> dp(N + 2, V<int>(3, INF));
    dp[0][0] = 0;

    FOR(i, 0, N + 1) {
        bool up = false, down = false;
        if ((i == 0 and S[i] == 'Y') or (i == N and S[2 * N - 1] == 'Y')) {
            up = true;
        }
        if (i != 0 and i != N and (S[2 * i] == 'Y' or S[2 * i - 1] == 'Y')) {
            up = true;
        }
        if ((i == 0 and S[2 * N] == 'Y') or (i == N and S[4 * N - 1] == 'Y')) {
            down = true;
        }
        if (i != 0 and i != N and (S[2 * N + 2 * i] == 'Y' or S[2 * N + 2 * i - 1] == 'Y')) {
            down = true;
        }
        
        FOR(j, 0, 3) {
            if (not up and not down) {
                chmin(dp[i + 1][j], dp[i][j]);
            }
            if (up and not down) {
                if (j == 0) {
                    chmin(dp[i + 1][0], dp[i][j] + 1);
                    chmin(dp[i + 1][1], dp[i][j] + 1);
                }
                if (j == 1) {
                    chmin(dp[i + 1][0], dp[i][j] + 1);
                    chmin(dp[i + 1][1], dp[i][j] + 1);
                }
                if (j == 2) {
                    chmin(dp[i + 1][0], dp[i][j] + 2);
                    chmin(dp[i + 1][1], dp[i][j] + 2);
                }
            }
            if (not up and down) {
                if (j == 0) {
                    chmin(dp[i + 1][1], dp[i][j] + 2);
                    chmin(dp[i + 1][2], dp[i][j] + 2);
                }
                if (j == 1) {
                    chmin(dp[i + 1][1], dp[i][j] + 1);
                    chmin(dp[i + 1][2], dp[i][j] + 1);
                }
                if (j == 2) {
                    chmin(dp[i + 1][1], dp[i][j] + 1);
                    chmin(dp[i + 1][2], dp[i][j] + 1);
                }
            }
            if (up and down) {
                if (j == 0) {
                    chmin(dp[i + 1][1], dp[i][j] + 2);
                    chmin(dp[i + 1][2], dp[i][j] + 2);
                }
                if (j == 1) {
                    chmin(dp[i + 1][0], dp[i][j] + 2);
                    chmin(dp[i + 1][1], dp[i][j] + 2);
                    chmin(dp[i + 1][2], dp[i][j] + 2);
                }
                if (j == 2) {
                    chmin(dp[i + 1][0], dp[i][j] + 2);
                    chmin(dp[i + 1][1], dp[i][j] + 2);
                }
            }
        }
    }

    return min(dp[N + 1][0], min(dp[N + 1][1] + 1, dp[N + 1][2] + 2)) + N;
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    int T;
    cin >> T;
    FOR(i, 0, T) {
        int N;
        cin >> N;
        string S;
        cin >> S;
        print(solve(N, S));
    }
    return 0;
}


Measured memory_bytes: 3520