#include <bits/stdc++.h>   using namespace std;   const int M = 1e6 + 10;   int n, ans;   void swap(int &x, int &y) {     int t = x;     x = y;     y = t;   }   int main() {     cin >> n;     vector<char> x(n), y(n);     for (auto &i : x) cin >> i;     for (auto &i : y) cin >> i;     for (int i = 0; i < n - 1; ++i) {       if (x[i] == y[i]) continue;       if (x[i + 1] == y[i + 1]) {         ans++;         continue;       }       if (x[i] == y[i + 1] && x[i + 1] == y[i])         swap(x[i], x[i + 1]), ans++;       else         ans++;     }     if (x[n - 1] != y[n - 1]) ans++;     cout << ans;     return 0;   }   