#include<bits/stdc++.h>
using namespace std;
const int N=100010;
int n;
char s1[N],t1[N];
char s2[N],t2[N];
int r1[N],a1[N],b1[N];
int r2[N],a2[N],b2[N];
int main(){
    freopen("edit.in","r",stdin);
    freopen("edit.out","w",stdout);
    ios::sync_with_stdio(0);
    cin.tie(0),cout.tie(0);
    int T;
    cin>>T;
    while(T--){
        cin>>n;
        cin>>s1+1>>s2+1>>t1+1>>t2+1;
        for(int i=n;i>=1;i--){
            a1[i]='1'-s1[i];
            b1[i]=s1[i]-'0';
            a2[i]='1'-s2[i];
            b2[i]=s2[i]-'0';
            if(i==n||t1[i]=='0'||t1[i+1]=='0')r1[i]=i;
            else{
                r1[i]=r1[i+1];
                a1[i]+=a1[i+1];
                b1[i]+=b1[i+1];
            }
            if(i==n||t2[i]=='0'||t2[i+1]=='0')r2[i]=i;
            else{
                r2[i]=r2[i+1];
                a2[i]+=a2[i+1];
                b2[i]+=b2[i+1];
            }
        }
        int x=1,y=1,ans=0;
        while(x<=n&&y<=n){
            int len=min(r1[x],r2[y])-max(x,y)+1;
            int aa=min(min(a1[x],a2[y]),len);
            ans+=aa;
            a1[x]-=aa,a2[y]-=aa,len-=aa;
            int bb=min(min(b1[x],b2[y]),len);
            ans+=bb;
            b1[x]-=bb,b2[y]-=bb,len-=bb;
            if(r1[x]==r2[y])x=r1[x]+1,y=r2[y]+1;
            else if(r1[x]<r2[y])x=r1[x]+1;
            else y=r2[y]+1;
        }
        cout<<ans<<'\n';
    }
    return 0;
}