#include <bits/stdc++.h>
using namespace std;

#define int long long

constexpr int maxn = 1e6 + 10;
constexpr int mod = 998244353;
constexpr int inf = 1e9;

inline void chmax(int &a, int b){a = max(a, b);}
inline void chmin(int &a, int b){a = min(a, b);}
inline void chadd(int &a, int b){a = (a + b) % mod;}

inline void solve()
{
  int n;
  cin >> n;
  string s, t;
  cin >> s >> t;

  string ns;
  int x = '0' ^ '1';
  for (int i = 0; i < n; i ++)
  {
    ns += s[i] ^ x;
  }
  int ans = 0, cnt = 2;
  for (int i = 0; i < n; i ++)
  {
    ans += s[i] != t[i];
    cnt += ns[i] != t[i];
  }
  cout << min(ans, cnt) << '\n';
}

signed main()
{
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  cout.tie(nullptr);
  
  solve();

  return 0;
}