#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using ul = unsigned long;

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int n;
    cin >> n;

    string sa, sb;
    cin.ignore();
    getline(cin, sa);
    getline(cin, sb);

    int res{sa[0] != sb[0]};
    for (int i = 0; i < n * 2 - 3; i += 2)
        res += (sa[i] != sa[i + 2]) != (sb[i] != sb[i + 2]);
    
    cout << ++res / 2 << "\n";

    return 0;
}