#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
int t, n, ans, tmp, sum1[4], sum2[4];
string s1, s2, t1, t2;
int main() {
#ifdef Lopera
	freopen("day0/edit/edit1.in", "r", stdin);
	freopen("edit.out", "w", stdout);
	freopen("edit.err", "w", stderr);
#else
	freopen("edit.in", "r", stdin);
	freopen("edit.out", "w", stdout);
#endif
	ios::sync_with_stdio(0);
	cin.tie(0), cout.tie(0);
	cin >> t;
	while(t--) {
		cin >> n >> s1 >> s2 >> t1 >> t2;
		s1.push_back('2');
		s2.push_back('3');
		t1.push_back('0');
		t2.push_back('0');
		ans = 0, sum1[0] = sum1[1] = sum2[0] = sum2[1] = 0;
		for(int i = 0, j = 0; i < n || j < n; ) {
			while(i < n && t1[i] != '0') {
				++sum1[s1[i] - '0'];
				++i;
			}
			while(j < n && t2[j] != '0') {
				++sum2[s2[j] - '0'];
				++j;
			}
			// cerr << i << " " << j << "!\n";
			// cerr << sum1[0] << " " << sum1[1] << " " << sum2[0] << " " << sum2[1] << '\n';
			if(i < j) {
				++sum1[s1[i] - '0'];
				++i;
				tmp = min(sum1[0], sum2[0]);
				sum1[0] -= tmp, sum2[0] -= tmp, ans += tmp;
				tmp = min(sum1[1], sum2[1]);
				sum1[1] -= tmp, sum2[1] -= tmp, ans += tmp;
				if(sum1[0]) sum2[1] -= sum1[0], sum1[0] = 0;
				if(sum1[1]) sum2[0] -= sum1[1], sum1[1] = 0;
			}
			else if(i > j) {
				++sum2[s2[j] - '0'];
				++j;
				tmp = min(sum1[0], sum2[0]);
				sum1[0] -= tmp, sum2[0] -= tmp, ans += tmp;
				tmp = min(sum1[1], sum2[1]);
				sum1[1] -= tmp, sum2[1] -= tmp, ans += tmp;
				if(sum2[0]) sum1[1] -= sum2[0], sum2[0] = 0;
				if(sum2[1]) sum1[0] -= sum2[1], sum2[1] = 0;
			}
			else {
				ans += min(sum1[0], sum2[0]) + min(sum1[1], sum2[1]) + (s1[i] == s2[j]);
				++i, ++j;
				sum1[0] = sum1[1] = sum2[0] = sum2[1] = 0;
			}
			// cerr << ans << '\n';
		}
		cout << ans << '\n';
	}
#ifdef Lopera
	cerr << '\n' << (double)clock() / CLOCKS_PER_SEC;
#endif
	return 0;
}

/*
g++ edit.cpp -o edit -std=c++14 -O2 -DLopera -static -Wall "-Wl,--stack=998244353"; ./edit
*/

/*
最后五分钟了，也调不出来了，写点东西吧
算是正常发挥吧，T3T4 没做出来
做出来了算奇迹吧
我能说什么呢
这个分要冲省队还是很难的
我也不知道要不要继续学 OI 了，学都学不动
好迷茫呀
唉唉
但是真心不喜欢 whk
看看省选能不能像去年一样创造奇迹吧
如果有奇迹就当是命运了，继续学吧
没有就退了吧，然后浑浑噩噩度过高中生活
废了
想哭啊
*/