#include<bits/stdc++.h>
using namespace std;
const int N=110000;
int t,n,ans,ss1[N],ss2[N],t1[N],t2[N],ct1[5],ct2[5];
char ch[N];
inline int read(){
	int z=0,f=1;
	char c=getchar();
	while(c<'0'||c>'9'){
		if(c=='-')f=-1;
		c=getchar();
	}
	while(c>='0'&&c<='9'){
		z=(z<<1)+(z<<3)+(c^48);
		c=getchar();
	}
	return z*f;
} 
int main(){
	freopen("edit.in","r",stdin);
	freopen("edit.out","w",stdout);
	t=read();
	while(t--){
		for(int i=0; i<=1; i++)ct1[i]=0,ct2[i]=0;
		ans=0;
		n=read();
		scanf("%s",ch);
		for(int i=0; i<n; i++)ss1[i+1]=ch[i]-'0';
		scanf("%s",ch);
		for(int i=0; i<n; i++)ss2[i+1]=ch[i]-'0';
		scanf("%s",ch);
		for(int i=0; i<n; i++)t1[i+1]=ch[i]-'0';
		scanf("%s",ch);
		for(int i=0; i<n; i++)t2[i+1]=ch[i]-'0';
		int l=1,r=1;
		while(l<=n||r<=n){
			while(t1[l]!=0&&l<=n)ct1[ss1[l]]++,l++;
			while(t2[r]!=0&&r<=n)ct2[ss2[r]]++,r++;
			if(l==r){
				if(ss1[l]==ss2[r]&&l<=n)ans++;
				ans+=min(ct1[1],ct2[1]);
				ans+=min(ct1[0],ct2[0]);
				ct1[1]=0,ct1[0]=0;
				ct2[1]=0,ct2[0]=0;
				l++,r++;
				//printf("%d %d \n",l,r);
			}
			if(l<r){
				ct1[ss1[l]]++,l++;
				if(ct1[1]<=ct2[1])ans+=ct1[1],ct2[1]-=ct1[1];
				else ans+=ct2[1],ct2[0]-=ct1[1]-ct2[1],ct2[1]=0;
				if(ct1[0]<=ct2[0])ans+=ct1[0],ct2[0]-=ct1[0];
				else ans+=ct2[0],ct2[1]-=ct1[0]-ct2[0],ct2[0]=0;
				ct1[1]=0,ct1[0]=0; 
				//printf("%d %d %d\n",l,r,ans);
			}
			if(l>r){
				ct2[ss2[r]]++,r++;
				if(ct2[1]<=ct1[1])ans+=ct2[1],ct1[1]-=ct2[1];
				else ans+=ct1[1],ct1[0]-=ct2[1]-ct1[1],ct1[1]=0;
				if(ct2[0]<=ct1[0])ans+=ct2[0],ct1[0]-=ct2[0];
				else ans+=ct1[0],ct1[1]-=ct2[0]-ct1[0],ct1[0]=0;
				ct2[1]=0,ct2[0]=0; 
				//printf("%d %d %d\n",l,r,ans);
			}
		}
		printf("%d\n",ans);
	}
}
/*
1
9
101111111
100111000
110111011
011111111
*/