#include<bits/stdc++.h>
using namespace std;
int ss1[2];
int ss2[2];
void slove()
{
    int n;
    string s1,s2,t1,t2;
    cin>>n;
    cin>>s1>>s2>>t1>>t2;
    int x=0,x1=0,x2=0;
    bool ok=0;
    long long ans=0;
    while(x<=n)
    {
        ok=false;
        if(x1<x2)
            while(x1<=n)
                if(ok&&t1[x1]=='0')
                    break;
                else if(t1[x1]=='0')
                {
                    ss1[s1[x1]-48]++;
                    x1++;
                    break;
                }
                else
                {
                    ok=1;
                    ss1[s1[x1]-48]++;
                    x1++;
                }
        else
            while(x2<=n)
                if(ok&&t2[x2]=='0')
                {
                    break;
                }
                else if(t2[x2]=='0')
                {
                    ss2[s2[x2]-48]++;
                    x2++;
                    break;
                }
                else
                {
                    ok=1;
                    ss2[s2[x2]-48]++;
                    x2++;
                }
        if(ss1[1]>ss2[1])
        {
            ans+=ss2[1];
            ss1[1]-=ss2[1];
            ss2[1]=0;
        }
        else
        {
            ans+=ss1[1];
            ss2[1]-=ss1[1];
            ss1[1]=0;
        }
        if(ss1[0]>ss2[0])
        {
            ans+=ss2[0];
            ss1[0]-=ss2[0];
            ss2[0]=0;
        }
        else
        {
            ans+=ss1[0];
            ss2[0]-=ss1[0];
            ss1[0]=0;
        }
        if(x1>x2)
        {
            if(ss1[1]==0)
            {
                ss1[0]-=ss2[1];
                ss2[1]=0;
            }
            else
            {
                ss1[1]-=ss2[0];
                ss2[0]=0;
            }
        }
        else if(x1==x2)
        {
            ss1[0]=ss1[1]=ss2[0]=ss2[1]=0;
        }
        else
        {
            if(ss2[1]==0)
            {
                ss2[0]-=ss1[1];
                ss1[1]=0;
            }
            else
            {

                ss2[1]-=ss1[0];
                ss1[0]=0;
            }
        }
        x=min(x1,x2);
    }
    cout<<ans<<endl;
    return;
}
int main()
{
    freopen("edit.in","r",stdin);
    freopen("edit.out","w",stdout);
    int T;
    cin>>T;
    for(int i=1;i<=T;i++)
    {
        slove();
    }
    return 0;
}