#include <bits/stdc++.h>

using namespace std;
 
typedef long long ll;
typedef long double ld;
typedef pair<int, int> Pii;
typedef pair<int, ll> Pil;
typedef pair<ll, ll> Pll;
typedef pair<ll, int> Pli;
typedef vector < vector<ll> > Mat;

#define fi first
#define se second

const ll MOD = 1e9 + 7;
const ll MOD2 = 998244353;
const ll MOD3 = 1812447359;
const ll INF = 1ll << 62;
const double PI = 2 * asin(1);

void yes() {printf("yes\n");}
void no() {printf("no\n");}
void Yes() {printf("Yes\n");}
void No() {printf("No\n");}
void YES() {printf("YES\n");}
void NO() {printf("NO\n");}

int N;
int S[505], T[505];
bool s[505], t[505];
bool visited[505][505], ans[505][505];

int main(){
  cin >> N;
  for (int i = 0; i < N; i++) cin >> S[i];
  for (int j = 0; j < N; j++) cin >> T[j];

  for (int i = 0; i < N; i++){
    if (S[i] == 1) continue;
    for (int j = 0; j < N; j++){
      if (S[i] == 0) ans[i][j] = false;
      else ans[i][j] = true, t[j] = true;
      visited[i][j] = true;
    }
  }
  for (int j = 0; j < N; j++){
    if (T[j] == 1) continue;
    for (int i = 0; i < N; i++){
      if (T[j] == 0) ans[i][j] = false;
      else ans[i][j] = true, s[i] = true;
      visited[i][j] = true;
    }
  }


  int res = 0;
  for (int i = 0; i < N; i++){
    for (int j = 0; j < N; j++){
      res += ans[i][j];
    }
  }

  int L = 0, R = 0;
  for (int i = 0; i < N; i++){
    if (S[i] == 1 && s[i] == false) L++;
    if (T[i] == 1 && t[i] == false) R++;
  }

  cout << res + max(L, R) << endl;


  return 0;
}