// 9:48 passed 90% examples
// 11:56 passed all examples
// there is just one step away from my AFO!
#include<bits/stdc++.h>
#define fi first
#define se second
#define debug(...) fprintf(stderr, __VA_ARGS__)
#define DEBUG debug("Passing %d line in %s\n", __LINE__, __FUNCTION__)

using namespace std;

typedef long long i64;
typedef unsigned long long u64;

int T;
int n, sum;
array<string, 2> s, t;
array<vector<int>, 2> vis;

struct Node
{
    int l, r, type, o;
    array<int, 2> num;
    Node(int _l, int _r, int _num0, int _num1, int _type, int _o): l(_l), r(_r), type(_type), o(_o), num{{_num0, _num1}} {}
    bool operator < (const Node &rhs) const { return r < rhs.r; }
};
vector<Node> a;

void clear()
{
    sum = 0;
    a.clear();
    for(int i: {0, 1})
        vis[i].clear();
}

void update(string &ss, string &tt, int o)
{
    // debug("update %d:\n", o);
    int lst = 1, num0 = (ss[1] == '0'), num1 = (ss[1] == '1');
    ss[0] = (char)((ss[1] - '0') ^ 1);
    for(int i = 2; i <= n + 1; i++)
    {
        if(i == n + 1 || (tt[i] != tt[i - 1]))
        {
            a.emplace_back(lst, i - 1, num0, num1, tt[i - 1] - '0', o);
            // debug("add: (%d, %d, %d, %d, %d)\n", lst, i - 1, num0, num1, tt[i - 1] - '0');
            lst = i, num0 = num1 = 0;
        }
        num0 += (ss[i] == '0');
        num1 += (ss[i] == '1');
    }
}

string get(string &str, int l, int r)
{
    if(l > r)
        return "";
    return str.substr(l, r - l + 1);
}

void solve()
{
    clear();
    cin >> n;
    cin >> s[0] >> s[1] >> t[0] >> t[1];
    s[0] = ' ' + s[0], s[1] = ' ' + s[1];
    t[0] = ' ' + t[0], t[1] = ' ' + t[1];

    for(int i: {0, 1})
        update(s[i], t[i], i);
    sort(a.begin(), a.end());

    array<string, 2> ans;
    ans.fill(string(n + 1, ' '));

    for(int i: {0, 1})
        vis[i].resize(n + 1);
    for(auto p: a)
    {
        if(p.type == 0)
        {
            for(int i = p.l; i <= p.r; i++)
                ans[p.o][i] = s[p.o][i], vis[p.o][i] = 1;
        }
    }

    array<int, 2> lst{{0, 0}};
    for(auto p: a)
    {
        int l = p.l, r = p.r, type = p.type, o = p.o, e = o ^ 1;
        auto num = p.num;
        // debug("%d, %d, %d, %d, %d, %d\n", l, r, num[0], num[1], type, o);
        if(type == 0)
            continue;
        else
        {
            auto add = [&](int x, int i) { ans[o][i] = (char)('0' + x), num[x]--; };
            for(int i = l; i <= r; i++)
            {
                if(!vis[e][i])
                    continue;
                int x = ans[e][i] - '0';
                if(num[x])
                    add(x, i);
                else
                    add(x ^ 1, i);
                vis[o][i] = 1;
            }
            for(int i = l; i <= r; i++)
            {
                if(vis[e][i])
                    continue;
                add(num[0] ? 0 : 1, i);
                vis[o][i] = 1;
            }
            // for(int i: {0, 1})
            //     ans[o] += string(num[i], (char)('0' + i));
        }
        lst[o] = r;
        // cerr << "ans0: " << ans[0] << '\n' << "ans1: " << ans[1] << '\n';
    }

    // cerr << ans[1] << '\n' << ans[2] << '\n';
    for(int i = 1; i <= n; i++)
        if(ans[0][i] == ans[1][i])
            sum++;
    cout << sum << endl;
}

int main()
{
    freopen("edit.in", "r", stdin);
    freopen("edit.out", "w", stdout);
    ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
    cin >> T;
    while(T--)
        solve();
    return 0;
}