#include <iostream>
#include <cstdio>
#include <string>
using namespace std;

const int N = 100010;
struct Node {
    int c0, c1;
    Node() {c0 = c1 = 0;}
} a1[N], a2[N];
int n;
string s1, s2, t1, t2;

void init() {
    int cnt1 = 0, cnt0 = 0;
    for (int i = n; ~i; i--) {
        if(i == 0 || t1[i] == '0') {
            if(i != 0) {
                if(s1[i] == '0') a1[i].c0 = 1, a1[i].c1 = 0;
                else a1[i].c1 = 1, a1[i].c0 = 0;
            }
            if(i < n && t1[i + 1] == '1') {
                a1[i + 1].c0 = cnt0, a1[i + 1].c1 = cnt1;
            }
            cnt0 = cnt1 = 0;
            continue;
        }
        if(s1[i] == '0') cnt0++;
        else cnt1++;
        a1[i].c0 = a1[i].c1 = 0;
    }

    for (int i = n; ~i; i--) {
        if(i == 0 || t2[i] == '0') {
            if(i != 0) {
                if(s2[i] == '0') a2[i].c0 = 1, a2[i].c1 = 0;
                else a2[i].c1 = 1, a2[i].c0 = 0;
            }
            if(i < n && t2[i + 1] == '1') {
                a2[i + 1].c0 = cnt0, a2[i + 1].c1 = cnt1;
            }
            cnt0 = cnt1 = 0;
            continue;
        }
        if(s2[i] == '0') cnt0++;
        else cnt1++;
        a2[i].c0 = a2[i].c1 = 0;
    }
}

int main() {
    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;
        cin >> s1 >> s2 >> t1 >> t2;
        s1 = ' ' + s1, s2 = ' ' + s2, t1 = ' ' + t1, t2 = ' ' + t2;
        init();
        // for (int i = 1; i <= n; i++) cout << a1[i].c0 << ' ' << a1[i].c1 << '\n';
        // cout << "---\n";
        // for (int i = 1; i <= n; i++) cout << a2[i].c0 << ' ' << a2[i].c1 << '\n';
        Node p1, p2;
        int ans = 0;
        for (int i = 1; i <= n; i++) {
            p1.c0 += a1[i].c0, p1.c1 += a1[i].c1;
            p2.c0 += a2[i].c0, p2.c1 += a2[i].c1;
            // cout << p1.c0 << ' ' << p1.c1 << ' ' << p2.c0 << ' ' << p2.c1 << '\n';
            if(p1.c1 && p2.c1) {
                ans++;
                p1.c1--, p2.c1--;
                continue;
            } else if(p1.c0 && p2.c0) {
                ans++;
                p1.c0--; p2.c0--;
                continue;
            } else {
                if(p1.c1 && p2.c0) p1.c1--, p2.c0--;
                else if(p1.c0 && p2.c1) p1.c0--, p2.c1--;
            }
        }
            
        cout << ans << '\n';
    }
    return 0;
}