#include<bits/stdc++.h>
using namespace std;
int t,n;
string s1,s2,t1,t2;
void solve(){
    int more1=0,more2=0,lf1=-1,lf2=-1,ans=0,tt1=0;
    for(int i=0;i<n;i++) tt1+=s1[i]+s2[i]-2*'0';
    for(int i=0;i<n;i++){
        if(i>lf1&&t1[i]=='1'){
            more1=0;
            int j=i;
            while(j<n&&t1[j]=='1') more1+=s1[j++]-'0';
            lf1=j;
          //  cout<<"(more1 change to"<<more1<<")";
        }
        if(i>lf2&&t2[i]=='1'){
            more2=0;
            int j=i;
            while(j<n&&t2[j]=='1') more2+=s2[j++]-'0';
            lf2=j;
          //  cout<<"(more2 change to"<<more2<<")";
        }
        if(t1[i]=='0'&&t2[i]=='0'&&s1[i]=='1'&&s2[i]=='1') ans++;
        if(t1[i]=='0'&&t2[i]=='1'&&s1[i]=='1'&&more2>0) ans++,more2--;
        if(t1[i]=='1'&&t2[i]=='0'&&s2[i]=='1'&&more1>0) ans++,more1--;
        if(t1[i]=='1'&&t2[i]=='1'&&more1>0&&more2>0) ans++,more2--,more1--;
        //cout<<more1<<" "<<more2<<" "<<ans<<"!"<<endl;
    }
    cout<<n-(tt1-ans*2)<<endl;
}
int main(){
    ios::sync_with_stdio(false);
    cin.tie(0),cout.tie(0);
    freopen("edit.in","r",stdin);
    freopen("edit.out","w",stdout);
    cin>>t;
    while(t--){
        cin>>n;
        cin>>s1>>s2>>t1>>t2;
        solve();
    }
    fclose(stdin);
    fclose(stdout);
}
/*
10
0110111100
1111111100
1110000100
0110111011
9
101111111
100111000
110111011
011111111
*/