#include<bits/extc++.h>
using namespace std;
#define ll long long
int n;
string s1,s2,t1,t2;

void solve(){
	cin>>n>>s1>>s2>>t1>>t2;
	s1=' '+s1,s2=' '+s2,t1=' '+t1,t2=' '+t2;
	int c10=0,c11=0,c20=0,c21=0,res=0;
	for(int l=1,r1=0,r2=0;l<=n;l++){
		while(r1<n&&(r1<l||t1[r1]=='1'&&t1[r1+1]=='1')){
			if(s1[++r1]=='1')c11++;
			else c10++;
		}
		while(r2<n&&(r2<l||t2[r2]=='1'&&t2[r2+1]=='1')){
			if(s2[++r2]=='1')c21++;
			else c20++;
		}
//		cerr<<l<<' '<<r1<<' '<<r2<<' '<<c10<<' '<<c11<<' '<<c20<<' '<<c21<<'\n';
		if(c11&&c21)c11--,c21--,res++;
		else if(c10&&c20)c10--,c20--,res++;
		else if(c11&&c20)c11--,c20--;
		else c10--,c21--;
		
	}
	cout<<res<<'\n';
}
int main(){
	ios::sync_with_stdio(0);
	cin.tie(0),cout.tie(0);
	freopen("edit.in","r",stdin);
	freopen("edit.out","w",stdout);
	int t;cin>>t;
	while(t-->0) solve();
	
}