#include <bits/stdc++.h>
using namespace std;
const int N=100005;
int T,n,l1[N],r1[N],d1[N],l2[N],r2[N],d2[N],p1,p2,ans,len;
char s1[N],s2[N],t1[N],t2[N];
int main(){
    freopen("edit.in","r",stdin);
    freopen("edit.out","w",stdout);
    scanf("%d",&T);
    while(T--){
        scanf("%d",&n);
        scanf("%s%s",s1+1,s2+1);
        scanf("%s%s",t1+1,t2+1);
        p1=0,p2=0,ans=0;
        for(int i=1;i<=n;i++){
            if(t1[i]=='1'){
                p1++;
                for(int j=i;j<=n;j++){
                    if(s1[j]=='1')
                        d1[p1]++;
                    if(j==n||t1[j+1]=='0'){
                        l1[p1]=i,r1[p1]=j;
                        i=j;
                        break;
                    }
                }
            }
            else{
                p1++;
                l1[p1]=i,r1[p1]=i;
                if(s1[i]=='1')
                    d1[p1]++;
            }
        }
        for(int i=1;i<=n;i++){
            if(t2[i]=='1'){
                p2++;
                for(int j=i;j<=n;j++){
                    if(s2[j]=='1')
                        d2[p2]++;
                    if(j==n||t2[j+1]=='0'){
                        l2[p2]=i,r2[p2]=j;
                        i=j;
                        break;
                    }
                }
            }
            else{
                p2++;
                l2[p2]=i,r2[p2]=i;
                if(s2[i]=='1')
                    d2[p2]++;
            }
        }
        for(int i=1,j=1;i<=p1&&j<=p2;){
            if(r1[i]==r2[j]){
                len=r1[i]-l1[i]+1;
                ans+=int(min(d1[i],d2[j])+len-max(d1[i],d2[j]));
                i++,j++;
            }
            else if(r1[i]>r2[j]){
                len=r2[j]-l2[j]+1;
                int t=min(len,min(d1[i],d2[j]));
                ans+=t+len-d2[j];
                d1[i]-=t,l1[i]=r2[j]+1;
                j++;
            }
            else{
                len=r1[i]-l1[i]+1;
                int t=min(len,min(d1[i],d2[j]));
                ans+=t+len-d1[i];
                d2[j]-=t,l2[j]=r1[i]+1;
                i++;
            }
        }
        printf("%d\n",ans);
        for(int i=1;i<=p1;i++)
            d1[i]=0;
        for(int i=1;i<=p2;i++)
            d2[i]=0;
    }
    return 0;
}