#include <iostream>
#include <algorithm>
#include <cstring>
#include <cmath>
#include <queue>
#include <set>
#include <map>
#include <cassert>
#include <random>
#include <chrono>
#include <ctime>
#include <numeric>

typedef long long ll;
typedef double lf;
typedef unsigned long long ull;

namespace FastIO
{
    const int MAXSIZE = (1 << 20);
    char buf[MAXSIZE], *p1, *p2;
    #define gc (p1 == p2 && (p2 = (p1 = buf) + fread(buf, 1, MAXSIZE, stdin), p1 == p2) ? EOF : *p1++)
    template <typename T>
    inline void Read(T &x)
    {
        x = 0; char ch = gc; bool f = 0;
        while (ch < '0' || ch > '9') { if (ch == '-') f = 1; ch = gc; }
        while (ch >= '0' && ch <= '9') x = x * 10 + (ch ^ 48), ch = gc;
        if (f) x = -x;
    }
}

using FastIO::Read;
using namespace std;

const int MAXN = 1e5 + 10;

int n;
char s[2][MAXN], t[2][MAXN];

int st1[MAXN], st2[MAXN], top1, top2;

int cnt[2][2], ans;

int main()
{
    // freopen("day0/edit/edit2.in", "r", stdin);
    freopen("edit.in", "r", stdin);
    freopen("edit.out", "w", stdout);
    ios::sync_with_stdio(0), cin.tie(0);
    int T;
    cin >> T;
    while (T--)
    {
        cin >> n >> s[0] + 1 >> s[1] + 1 >> t[0] + 1 >> t[1] + 1;
        top1 = 0;
        for (int i = 1; i <= n; i++)
            if (t[0][i] == '0') st1[++top1] = i;
        top2 = 0;
        for (int i = 1; i <= n; i++)
            if (t[1][i] == '0') st2[++top2] = i;
        st1[++top1] = st2[++top2] = n + 1, s[0][n + 1] = '0', s[1][n + 1] = '1';
        memset(cnt, 0, sizeof(cnt));
        ans = 0;
        int a = 1, b = 1;
        for (int i = 1, j = 1; i <= top1 || j <= top2;)
        {
            if (st1[i] == st2[j])
            {
                while (a < st1[i]) cnt[0][s[0][a] - '0']++, a++;
                while (b < st2[j]) cnt[1][s[1][b] - '0']++, b++;
                ans += min(cnt[0][0], cnt[1][0]) + min(cnt[0][1], cnt[1][1]);
                memset(cnt, 0, sizeof(cnt));
                ans += (s[0][st1[i]] == s[1][st2[j]]), a++, b++;
                i++, j++;
            }
            else if (st1[i] < st2[j])
            {
                while (a <= st1[i]) cnt[0][s[0][a] - '0']++, a++;
                while (b < st2[j]) cnt[1][s[1][b] - '0']++, b++;
                int x = min(cnt[0][0], cnt[1][0]), y = min(cnt[0][1], cnt[1][1]);
                cnt[1][0] -= cnt[0][0], cnt[1][1] -= cnt[0][1], cnt[0][0] = cnt[0][1] = 0;
                ans += x + y;
                if (cnt[1][0] < 0) cnt[1][1] += cnt[1][0], cnt[1][0] = 0;
                if (cnt[1][1] < 0) cnt[1][0] += cnt[1][1], cnt[1][1] = 0;
                i++;
            }
            else
            {
                while (a < st1[i]) cnt[0][s[0][a] - '0']++, a++;
                while (b <= st2[j]) cnt[1][s[1][b] - '0']++, b++;
                int x = min(cnt[0][0], cnt[1][0]), y = min(cnt[0][1], cnt[1][1]);
                cnt[0][0] -= cnt[1][0], cnt[0][1] -= cnt[1][1], cnt[1][0] = cnt[1][1] = 0;
                ans += x + y;
                if (cnt[0][0] < 0) cnt[0][1] += cnt[0][0], cnt[0][0] = 0;
                if (cnt[0][1] < 0) cnt[0][0] += cnt[0][1], cnt[0][1] = 0;
                j++;
            }
            // cout << st1[i] << ' ' << st2[j] << ' ' << ans << '\n';
            // cout << a << ' ' << b << ' ';
            // for (int x = 0; x < 2; x++)
            //     for (int y = 0; y < 2; y++) cout << cnt[x][y] << ' ';
            // cout << '\n';
        }
        cout << ans << '\n';
    }
    return 0;
}