#include<bits/stdc++.h>
using namespace std;
#define ALL(x) x.begin(),x.end()
#define rep(i,n) for(int i=0;i<(n);i++)
#define debug(v) cout<<#v<<":";for(auto x:v){cout<<x<<' ';}cout<<endl;
#define mod 1000000007
using ll=long long;
const int INF=1000000000;
const ll LINF=1001002003004005006ll;
int dx[]={1,0,-1,0},dy[]={0,1,0,-1};
// ll gcd(ll a,ll b){return b?gcd(b,a%b):a;}
template<class T>bool chmax(T &a,const T &b){if(a<b){a=b;return true;}return false;}
template<class T>bool chmin(T &a,const T &b){if(b<a){a=b;return true;}return false;}
 
struct IOSetup{
    IOSetup(){
        cin.tie(0);
        ios::sync_with_stdio(0);
        cout<<fixed<<setprecision(12);
    }
} iosetup;

template<typename T1,typename T2>
ostream &operator<<(ostream &os,const pair<T1,T2>&p){
    os<<p.first<<" "<<p.second;
    return os;
}
 
template<typename T>
ostream &operator<<(ostream &os,const vector<T>&v){
    for(int i=0;i<(int)v.size();i++) os<<v[i]<<(i+1==(int)v.size()?"":" ");
    return os;
}

template<typename T1,typename T2>
istream &operator>>(istream &is,pair<T1,T2>&p){
    is>>p.first>>p.second;
    return is;
}

template<typename T>
istream &operator>>(istream &is,vector<T>&v){
    for(T &x:v)is>>x;
    return is;
}


signed main(){
    int n;cin>>n;
    int a[n][n];
    rep(i,n)rep(j,n)a[i][j]=-1;
    int h=0,w=0;

    rep(i,n){
        int s;cin>>s;
        if(s==0){
            rep(j,n)a[i][j]=0;
        }else if(s==1){
            h++;
        }else{
            rep(j,n)a[i][j]=1;
        }
    }
    rep(j,n){
        int t;cin>>t;
        if(t==0){
            rep(i,n)a[i][j]=0;
        }else if(t==1){
            w++;
        }else{
            rep(i,n)a[i][j]=1;
        }
    }

    h=0,w=0;// matigaeta

    rep(i,n){
        bool f=false;
        rep(j,n){
            if(a[i][j]==-1)f=true;
        }
        h+=f;
    }
    rep(j,n){
        bool f=false;
        rep(i,n){
            if(a[i][j]==-1)f=true;
        }
        w+=f;
    }

    int res=0;
    rep(i,n)rep(j,n)if(a[i][j]==1)res++;
    res+=min(h,w);
    cout<<res<<endl;
    return 0;
}