#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <queue>
#include <iomanip>
#define Min(x, y) ((x)<(y)?(x):(y))
#define Max(x, y) ((x)<(y)?(y):(x))
#define abs(x) ((x)<0?-(x):(x))
#define lowbit(x) ((x)&-(x))

typedef long long ll;
typedef unsigned long long ull;
typedef __int128 i128;

using namespace std;

const int N = 1e5 + 5;

struct Seg {
	int l, r, cnt0, cnt1;
};

int n, m1, m2;
char s1[N], s2[N], t1[N], t2[N];
Seg q1[N], q2[N];

int main(void) {
	freopen("edit.in", "r", stdin);
	freopen("edit.out", "w", stdout);
	
	ios::sync_with_stdio(false);

	int T; cin >> T;
	while (T--) {
		cin >> n; int ans = 0;
		cin >> s1 + 1 >> s2 + 1 >> t1 + 1 >> t2 + 1;
		m1 = 0; for (int i=1; i<=n; ++i) {
			if (t1[i] == '0' || t1[i] != t1[i-1]) q1[++m1].l = i;
			q1[m1].r = i; q1[m1].cnt0 += (s1[i] == '0'); q1[m1].cnt1 += (s1[i] == '1');
		}
		m2 = 0; for (int i=1; i<=n; ++i) {
			if (t2[i] == '0' || t2[i] != t2[i-1]) q2[++m2].l = i;
			q2[m2].r = i; q2[m2].cnt0 += (s2[i] == '0'); q2[m2].cnt1 += (s2[i] == '1');
		}
		ans = 0; for (int i=1,j=1,plus,tmp; i<=m1; ++i) {
			while (j <= m2 && q2[j].r <= q1[i].r) {
				plus = tmp = 0;
				tmp = Min(q1[i].cnt1, Min(q2[j].cnt1, q2[j].r - q1[i].l + 1 - plus));
				q1[i].cnt1 -= tmp; q2[j].cnt1 -= tmp; ans += tmp; plus += tmp;
				tmp = Min(q1[i].cnt0, Min(q2[j].cnt0, q2[j].r - q1[i].l + 1 - plus));
				q1[i].cnt0 -= tmp; q2[j].cnt0 -= tmp; ans += tmp;
				++j;
			}
			if (j <= m2 && q2[j].l <= q1[i].r) {
				plus = tmp = 0;
				tmp = Min(q1[i].cnt1, Min(q2[j].cnt1, q1[i].r - q2[j].l + 1 - plus));
				q1[i].cnt1 -= tmp; q2[j].cnt1 -= tmp; ans += tmp; plus += tmp;
				tmp = Min(q1[i].cnt0, Min(q2[j].cnt0, q1[i].r - q2[j].l + 1 - plus));
				q1[i].cnt0 -= tmp; q2[j].cnt0 -= tmp; ans += tmp;
			}
		}
		for (int i=1; i<=m1; ++i) q1[i].cnt0 = q1[i].cnt1 = 0;
		for (int i=1; i<=m2; ++i) q2[i].cnt0 = q2[i].cnt1 = 0;
		cout << ans << '\n';
	}
	return 0;
}