#include <cstdio>
using namespace std;
const int maxn = 100010;
char s[2][maxn] = {0}, a[2][maxn] = {0};
int c[2][maxn] = {0};
int min (int a, int b) {
    return (a < b) ? a : b;
}
int n, res = 0;
void swap (char &x, char &y) {
    char t = x;
    x = y;
    y = t;
}
void dfs (int now) {
    if (now == n) {
        int cnt = 0;
        for (int i = 0; i < n; i ++) {
            if (s[0][i] == s[1][i]) {
                cnt ++;
            }
        }
        if (res < cnt) {
            res = cnt;
        }
        return;
    }
    dfs (now + 1);
    if (a[0][now] == '1' && a[0][now + 1] == '1') {
        swap(s[0][now], s[0][now + 1]);
        dfs(now + 1);
    }
    if (a[1][now] == '1' && a[1][now + 1] == '1') {
        swap(s[1][now], s[1][now + 1]);
        dfs(now + 1);
    }
    if (a[0][now] == '1' && a[0][now + 1] == '1') {
        swap(s[0][now], s[0][now + 1]);
        dfs(now + 1);
    }
    if (a[1][now] == '1' && a[1][now + 1] == '1') {
        swap(s[1][now], s[1][now + 1]);
    }
}
int fa[maxn << 1] = {0}, lf[maxn << 1] = {0}, rg[maxn << 1] = {0};
int buc[maxn << 1][2] = {0};
int find (int x) {
    return (fa[x] == x) ? x : (fa[x] = find(fa[x]));
}
int max (int a, int b) {
    return a > b ? a : b;
}
void solve5() {
    for (int i = 0; i < 2 * n; i ++) {
        fa[i] = i;
        lf[i] = (i > n) ? (i - n) : i;
        rg[i] = (i > n) ? (i - n) : i;
        buc[i][0] = 0;
        buc[i][1] = 0;
    }
    // printf("1\n");
    for (int i = 0; i < n; ) {
        if (a[0][i] == '0') {
            buc[i][s[0][i] - '0'] ++;
            i ++;
            continue;
        }
        int j = i;
        while (a[0][j] == '1' && j < n) {
            fa[j] = i;
            buc[i][s[0][j] - '0'] ++;
            j ++;
            // printf("///////\n");
        }
        rg[i] = j - 1;
        i = j;
        // printf("[[+]]\n");
    }
    // printf("2\n");
    for (int i = 0; i < n; ) {
        if (a[1][i] == '0') {
            buc[i + n][s[1][i] - '0'] ++;
            i ++;
            continue;
        }
        int j = i;
        while (a[1][j] == '1' && j < n) {
            fa[j + n] = i + n;
            buc[i + n][s[1][j] - '0'] ++;
            j ++;
        }
        rg[i + n] = j - 1;
        i = j;
    }

    for (int i = 0; i < n; i ++) {
        if (a[0][i] == '0') {
            if (a[1][i] == '0') {
                res += ((s[0][i] == s[1][i]) ? 1 : 0);
            }
            else {
                int aa = find(i + n);
                if (s[0][i] == '0' && buc[aa][0] != 0) {
                    res ++;
                    buc[i][0] --;
                    buc[aa][0] --;
                }
                else if (s[0][i] == '1' && buc[aa][1] != 0) {
                    res ++;
                    buc[i][1] --;
                    buc[aa][1] --;
                }
            }
        }
        else {
            if (a[1][i] == '0') {
                int aa = find(i);
                if (s[1][i] == '0' && buc[aa][0] != 0) {
                    res ++;
                    buc[aa][0] --;
                    buc[i + n][0] --;
                }
                else if (s[1][i] == '1' && buc[aa][1] != 0) {
                    res ++;
                    buc[aa][1] --;
                    buc[i + n][1] --;
                }
            }
            else {
                int aa = find(i), bb = find(i + n);
                int t = min(buc[aa][0], buc[bb][0]), t_ = min(buc[aa][1], buc[bb][1]);
                res += t + t_;
                buc[aa][0] -= t;
                buc[bb][0] -= t;
                buc[aa][1] -= t_;
                buc[bb][1] -= t_;
                // if (s[0][i] == '0' && buc[bb][0] != 0) {
                //     res ++;
                //     buc[aa][0] --;
                //     buc[bb][0] --;
                // }
                // else if (s[0][i] == '1' && buc[bb][1] != 0) {
                //     res ++;
                //     buc[aa][1] --;
                //     buc[bb][1] --;
                // }
            }
        }
    }
    printf("%d\n", res);
}
int main () {
    freopen("edit.in", "r", stdin);
    freopen("edit.out", "w", stdout);
    int _;
    scanf("%d", &_);
    while (_ --) {
        res = 0;
        // printf("/////////\n");
        scanf("%d", &n);
        scanf("%s", s[0]);
        scanf("%s", s[1]);
        scanf("%s", a[0]);
        scanf("%s", a[1]);
        bool okA = true;
        for (int i = 1; i < n; i ++) {
            if (s[0][0] != s[0][i]) {
                okA = false;
            }
        }
        bool okB = true;
        for (int i = 0; i < n; i ++) {
            if (a[0][i] != a[1][i]) {
                okB = false;
            }
        }
        int cnt00 = 0, cnt01 = 0;
        for (int i = 0; i < n; i ++) {
            if (a[0][i] == '0') {
                cnt00 ++;
            }
            if (a[1][i] == '0') {
                cnt01 ++;
            }
        }
        if (n <= 10) {
            dfs(0);
            printf("%d\n", res);
        }
        else if (okA) {
            int cnt = 0;
            for (int i = 0; i < n; i ++) {
                if (s[0][i] == s[1][i]) {
                    cnt ++;
                }
            }
            printf("%d\n", cnt);
        }
        else if (okB) {
            for (int i = 0; i < n;) {
                if (a[0][i] == '0') {
                    res += (s[0][i] == s[1][i]) ? 1 : 0;
                    i ++;
                    continue;
                }
                int j = i, cnt1 = 0, cnt2 = 0;
                while (a[0][j] == '1') {
                    cnt1 += (s[0][j] - '0');
                    cnt2 += (s[1][j] - '0');
                    j ++;
                }
                res += min(cnt1, cnt2) + min(j - i - cnt1, j - i - cnt2);
                i = j;
            }
            printf("%d\n", res);
        }
        else if (cnt00 == 1 && cnt01 == 1) { // okC.
            int cnt0[4] = {0}, cnt1[4] = {0};
            int i = 0;
            for (; i < n; i ++) {
                cnt0[0] += (s[0][i] == '0') ? 1 : 0;
                cnt1[0] += (s[0][i] - '0');
                if (a[0][i] == '0') {
                    break;
                }
            }
            for (int k = i + 1; k < n; k ++) {
                cnt0[1] += (s[0][k] == '0') ? 1 : 0;
                cnt1[1] += (s[0][k] - '0');
            }
            int j = 0;
            for (; j < n; j ++) {
                if (a[1][j] == '0') {
                    break;
                }
                cnt0[2] += (s[1][j] == '0') ? 1 : 0;
                cnt1[2] += (s[1][j] - '0');
            }
            for (int k = j; k < n; k ++) {
                cnt0[3] += (s[1][k] == '0') ? 1 : 0;
                cnt1[3] += (s[1][k] - '0');
            }
            int t = min(cnt0[0], cnt0[2]), t_ = min(cnt1[0], cnt1[2]);
            res += t + t_;
            cnt0[0] -= t;
            cnt0[2] -= t;
            cnt1[0] -= t_;
            cnt1[2] -= t_;
            // printf("%d\n", res);
            t = min(cnt0[1], cnt0[3]), t_ = min(cnt1[1], cnt1[3]);
            res += t + t_;
            cnt0[1] -= t;
            cnt0[3] -= t;
            cnt1[1] -= t_;
            cnt1[3] -= t_;
            // printf("%d\n", res);
            if (i < j) {
                t = min(cnt0[1], cnt0[2]), t_ = min(cnt1[1], cnt1[2]);
                res += (t + t_ > j - i - 1) ? (j - i - 1) : (t + t_);
                // cnt0[1] -= t;
                // cnt0[2] -= t;
                // cnt1[1] -= t_;
                // cnt1[2] -= t_;
            }
            else {
                t = min(cnt0[0], cnt0[3]), t_ = min(cnt1[0], cnt1[3]);
                res += (t + t_ > i - j - 1) ? (i - j - 1) : (t + t_);
                // cnt0[0] -= t;
                // cnt0[3] -= t;
                // cnt1[0] -= t_;
                // cnt1[3] -= t_;
            }
            printf("%d\n", res);
        }
        else {
            solve5();
        }
    }

    return 0;
}