#include<bits/stdc++.h>
using namespace std;
using vi=vector<int>;
const int N=1e5+5;
int n,ans=0,ct[2],s[2],x,y;
char s1[N],s2[N],t1[N],t2[N];
int pr1[N][2],pr2[N][2];
int l1[N],l2[N],r1[N],r2[N];
void solve()
{
    cin>>n>>s1+1>>s2+1>>t1+1>>t2+1;ans=0;
    for(int i=1;i<=n;i++)
    {
        pr1[i][0]=pr1[i-1][0];
        pr1[i][1]=pr1[i-1][1];
        pr2[i][0]=pr2[i-1][0];
        pr2[i][1]=pr2[i-1][1];
        pr1[i][s1[i]-'0']++;
        pr2[i][s2[i]-'0']++;
    }ct[0]=ct[1]=0;x=y=0;
    for(int i=1;i<=n;i++)
    {
        if(t1[i]=='0')
        {
            x++;
            l1[x]=r1[x]=i;
            continue;
        }l1[++x]=i;
        while(i+1<=n&&t1[i+1]!='0')i++;
        r1[x]=i;
    }for(int i=1;i<=n;i++)
    {
        if(t2[i]=='0')
        {
            y++;
            l2[y]=r2[y]=i;
            continue;
        }l2[++y]=i;
        while(i+1<=n&&t2[i+1]!='0')i++;
        r2[y]=i;
    }for(int i=1,j=0;i<=x;i++)
    {
        s[0]=pr1[r1[i]][0]-pr1[l1[i]-1][0];
        s[1]=pr1[r1[i]][1]-pr1[l1[i]-1][1];
        while(j+1<=y&&l2[j+1]<=r1[i])
        {
            //cout<<ct[0]<<' '<<ct[1]<<'|'<<s[0]<<' '<<s[1]<<'\n';
            int cnt=min(ct[0],s[0]);
            ans+=cnt,ct[0]-=cnt,s[0]-=cnt;
            cnt=min(ct[1],s[1]);
            ans+=cnt,ct[1]-=cnt,s[1]-=cnt;
            if(ct[0])s[1]-=ct[0],ct[0]=0;
            if(ct[1])s[0]-=ct[1],ct[1]=0;
            j++;
            ct[0]=pr2[r2[j]][0]-pr2[l2[j]-1][0];
            ct[1]=pr2[r2[j]][1]-pr2[l2[j]-1][1];
        }//cout<<"===\n";
        //cout<<ct[0]<<' '<<ct[1]<<'|'<<s[0]<<' '<<s[1]<<'\n';
        //cout<<"====\n";
        int cnt=min(ct[0],s[0]);
        ans+=cnt,ct[0]-=cnt,s[0]-=cnt;
        cnt=min(ct[1],s[1]);
        ans+=cnt,ct[1]-=cnt,s[1]-=cnt;
        if(s[0])ct[1]-=s[0],s[0]=0;
        if(s[1])ct[0]-=s[1],s[1]=0;
    }cout<<ans<<'\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--)solve();return 0;

}
/*
1
10
0110111100
1111111100
1110000100
0110111011
*/