#include<bits/stdc++.h>
using namespace std;
int T,n,ans;
struct Block{
	string s,t;
	int ed,cnt[6];
	inline void Ins(){
		s = '.' + s,t = '.' + t;
		return ;
	}
	inline void Scan(int nowst){
		if(nowst <= ed)return ;
		for(int i = nowst;i <= n;i++){
			if(t[i] == '0')break;//都没有扫到最后一位
			cnt[s[i] - '0']++;
			ed = i;
		}
		return ;
	}
	inline void Append(){
		ed++;
		cnt[s[ed] - '0']++;
		return ;
	}
}b[6];
inline void Execute(Block& b1,Block& b2){
	if(b1.cnt[0] >= b2.cnt[0] && b1.cnt[1] >= b2.cnt[1]){
//		cerr<<"case1"<<endl;
		ans += b2.cnt[0] + b2.cnt[1];
		b1.cnt[0] -= b2.cnt[0],b1.cnt[1] -= b2.cnt[1];
	}else if(b1.cnt[0] >= b2.cnt[0]){
//		cerr<<"case2"<<endl;
		ans += b2.cnt[0] + b1.cnt[1];
		b1.cnt[0] -= b2.cnt[0] + b2.cnt[1] - b1.cnt[1];
		b1.cnt[1] = 0;
	}else if(b1.cnt[1] >= b2.cnt[1]){
//		cerr<<"case3"<<endl;
		ans += b2.cnt[1] + b1.cnt[0];
		b1.cnt[1] -= b2.cnt[1] + b2.cnt[0] - b1.cnt[0];
		b1.cnt[0] = 0;
	}else{
//		cerr<<"ERRRRRRRRRRRRRRRRRRRRRRRR"<<endl;
	}
	b2.cnt[0] = b2.cnt[1] = 0;
	return ;
}
int main(){
	ios::sync_with_stdio(false);
	cin.tie(0),cout.tie(0);
	freopen("edit.in","r",stdin);
	freopen("edit.out","w",stdout);
	cin>>T;
	while(T--){
		cin>>n>>b[1].s>>b[2].s>>b[1].t>>b[2].t;
		ans = 0;
		b[1].Ins(),b[2].Ins();
		b[1].ed = b[2].ed = 0;
		while(b[1].ed != n || b[2].ed != n){
			int st = min(b[1].ed,b[2].ed) + 1;
			b[1].Scan(st),b[2].Scan(st);
//			cerr<<"scan from "<<st<<"reach "<<b[1].ed<<" and "<<b[2].ed<<endl;
//			cerr<<"cnt ("<<b[1].cnt[0]<<","<<b[1].cnt[1]<<") and ";
//			cerr<<"cnt ("<<b[2].cnt[0]<<","<<b[2].cnt[1]<<")"<<endl;
			if(b[1].ed == b[2].ed){
//				cerr<<"MAIN CASE 1"<<endl;
				Execute(b[1],b[2]);
				if(b[1].ed != n){
					b[1].ed++,b[2].ed++;
					if(b[1].s[b[1].ed] == b[2].s[b[2].ed])ans++;
				}
			}else if(b[1].ed > b[2].ed){
//				cerr<<"MAIN CASE 2"<<endl;
				b[2].Append();
				Execute(b[1],b[2]);
			}else if(b[1].ed < b[2].ed){
//				cerr<<"MAIN CASE 3"<<endl;
				b[1].Append();
				Execute(b[2],b[1]);
			}
//			cerr<<"end reach "<<b[1].ed<<","<<b[2].ed<<" ans "<<ans<<endl;
//			cerr<<"cnt ("<<b[1].cnt[0]<<","<<b[1].cnt[1]<<") and ";
//			cerr<<"cnt ("<<b[2].cnt[0]<<","<<b[2].cnt[1]<<")"<<endl;
//			cerr<<"---------------------------------"<<endl;
		}
		cout<<ans<<endl;
	}
	return 0;
}
//AKANO2024
/*
9:44
打完T1
疑似有点太菜了
签到签的有点久喵uwu
*/