// #define DBEUG
#ifdef DEBUG
#define _GLIBCXX_DEBUG 1
#endif
#include <bits/stdc++.h>
using namespace std;
// #undef LOCAL
bool Mbg;
namespace Anonyme {
#define QwQ01AwA return 0
using i64 = long long;
#define mset(a, x) memset(begin(a), x, sizeof(a))
#define file(x) freopen(x ".in", "r", stdin), freopen(x ".out", "w", stdout)
template <class T> bool ckmax(T &x, const T &y) {return x < y ? (x = y, 1) : 0;}
template <class T> bool ckmin(T &x, const T &y) {return x > y ? (x = y, 1) : 0;}

const int N = 1e5 + 5;
int n, na, nb;
string s1, s2, t1, t2;
array<int, 4> va[N], vb[N];

void solve() {
	cin >> n;
	cin >> s1 >> s2;
	cin >> t1 >> t2;
	na = nb = 0;
	for (int i = 0, j = 0; i < n; i = j) {
		if (t1[i] == '0') {
			int c0 = s1[i] == '0', c1 = s1[i] == '1';
			va[++na] = {i, i, c0, c1};
			j++;
			continue;
		}
		while (j < n && t1[j] == '1') j++;
		int c0 = 0, c1 = 0;
		for (int k = i; k < j; k++) c0 += s1[k] == '0', c1 += s1[k] == '1';
		va[++na] = {i, j - 1, c0, c1};
	}
	for (int i = 0, j = 0; i < n; i = j) {
		if (t2[i] == '0') {
			int c0 = s2[i] == '0', c1 = s2[i] == '1';
			vb[++nb] = {i, i, c0, c1};
			j++;
			continue;
		}
		while (j < n && t2[j] == '1') j++;
		int c0 = 0, c1 = 0;
		for (int k = i; k < j; k++) c0 += s2[k] == '0', c1 += s2[k] == '1';
		vb[++nb] = {i, j - 1, c0, c1};
	}

	// cerr << na << ' ' << nb << '\n';
	int i = 1, j = 1;
	int ans = 0;
	while (i <= na && j <= nb) {
		if (va[i][1] > vb[j][1]) {
			// assert(va[i][0] <= vb[j][1]);
			int c0 = min(va[i][2], vb[j][2]);
			int c1 = min(va[i][3], vb[j][3]);
			ans += c0 + c1;
			va[i][2] -= c0, va[i][3] -= c1;
			vb[j][2] -= c0, vb[j][3] -= c1;
			if (vb[j][2] || vb[j][3]) {
				int p = vb[j][2] + vb[j][3];
				if (va[i][2]) va[i][2] -= p;
				else if (va[i][3]) va[i][3] -= p;
				// else assert(0);
			}
			j++;
		} else if (va[i][1] < vb[j][1]) {
			// assert(vb[j][0] <= va[i][1]);
			int c0 = min(va[i][2], vb[j][2]);
			int c1 = min(va[i][3], vb[j][3]);
			ans += c0 + c1;
			va[i][2] -= c0, va[i][3] -= c1;
			vb[j][2] -= c0, vb[j][3] -= c1;
			if (va[i][2] || va[i][3]) {
				int p = va[i][2] + va[i][3];
				if (vb[j][2]) vb[j][2] -= p;
				else if (vb[j][3]) vb[j][3] -= p;
				// else assert(0);
			}
			i++;		
		} else {
			int c0 = min(va[i][2], vb[j][2]);
			int c1 = min(va[i][3], vb[j][3]);
			ans += c0 + c1;
			i++, j++;			
		}
	}
	// assert(i == na + 1 && j == nb + 1);
	cout << ans << '\n';
}

void main01() {
	file("edit");
	#ifdef LOCAL
	// file("edit2");
	#endif 
	cin.tie(nullptr) -> sync_with_stdio(false);
	int t;
	cin >> t;
	while (t--) solve();
}}
bool Med;
signed main() {
	Anonyme::main01();
	#ifdef LOCAL
	cerr << endl;
	cerr << "Time: " << 1.0 * clock() / CLOCKS_PER_SEC << "s" << endl;
	cerr << "Memory: " << abs(&Mbg - &Med) / 1048576.0 << "mb"<< endl;
	#endif
	QwQ01AwA;
}