#include<bits/stdc++.h>
using namespace std;
#define rep(x,l,r) for(int x=(l);x<=(r);x++)
#define per(x,l,r) for(int x=(r);x>=(l);x--)
#define pc(x) putchar(x)
#define gc() getchar()
#define ll long long
#define ms(x,y) memset(x,y,sizeof(x))
#define msz(x) memset(x,0,sizeof(x))
#define msu(x) memset(x,0x3f,sizeof(x))
#define msl(x) memset(x,0xcf,sizeof(x))
#define fi first
#define se second
const int inf=0x3f3f3f3f;
const ll infll=0x3f3f3f3f3f3f3f3f;
ll read(){
    ll x=0,f=1;char c=gc();
    while(!isdigit(c)){if(c=='-')f=-1;c=gc();}
    while(isdigit(c)){x=10*x+c-'0';c=gc();}
    return x*f;
}
template<class A,class B> void ckmax(A &x,B y){x=(x<y)?y:x;}
template<class A,class B> void ckmin(A &x,B y){x=(x>y)?y:x;}
/*--------------------*/
string s1,s2,t1,t2;
pair<int,int> a[100100],b[100100];
int t,n;
int main(){
    freopen("edit.in","r",stdin);
    freopen("edit.out","w",stdout);
    ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    cin>>t;
    while(t--){
        cin>>n;
        cin>>s1>>s2>>t1>>t2;
        int z=0,oe=0,pre=1;
        s1=" "+s1;s2=" "+s2;
        t1=" "+t1;t2=" "+t2;
        rep(i,0,n)a[i]={0,0},b[i]={0,0};
        rep(i,1,n){
            if(t1[i]=='0'){
                a[pre]={z,oe};
                pre=i+1;
                z=0;oe=0;
            }else{
                if(s1[i]=='0')z++;
                else oe++;
            }
        }a[pre]={z,oe};
        z=0;oe=0;pre=1;
        rep(i,1,n){
            if(t2[i]=='0'){
                b[pre]={z,oe};
                pre=i+1;
                z=0;oe=0;
            }else{
                if(s2[i]=='0')z++;
                else oe++;
            }
        }b[pre]={z,oe};
        int ans=0;
        rep(i,1,n){
            if(t1[i]=='1'&&t2[i]=='1'){
                if(a[i].fi>0&&b[i].fi>0){
                    a[i].fi--;b[i].fi--;
                    ans++;
                }else if(a[i].se>0&&b[i].se>0){
                    a[i].se--;b[i].se--;
                    ans++;
                }else{
                    if(a[i].fi>0&&b[i].se>0)a[i].fi--,b[i].se--;
                    else if(a[i].se>0&&b[i].fi>0)a[i].se--,b[i].fi--;
                }
                if(t1[i+1]=='1')a[i+1]=a[i];
                if(t2[i+1]=='1')b[i+1]=b[i];
            }else if(t1[i]=='1'&&t2[i]=='0'){
                if(s2[i]=='0'){
                    if(a[i].fi>0)a[i].fi--,ans++;
                    else a[i].se--;
                }else{
                    if(a[i].se>0)a[i].se--,ans++;
                    else a[i].fi--;
                }
                if(t1[i+1]=='1')a[i+1]=a[i];
            }else if(t1[i]=='0'&&t2[i]=='1'){
                if(s1[i]=='0'){
                    if(b[i].fi>0)b[i].fi--,ans++;
                    else b[i].se--;
                }else{
                    if(b[i].se>0)b[i].se--,ans++;
                    else b[i].fi--;
                }
                if(t2[i+1]=='1')b[i+1]=b[i];
            }else if(t1[i]=='0'&&t2[i]=='0'){
                if(s1[i]==s2[i])ans++;
            }
        }
        cout<<ans<<'\n';
    }
}