#include <bits/stdc++.h>

using namespace std;

int main()
{
    int n;
    cin >> n;

    string a, b;
    cin >> a >> b;

    vector<int> paritas(n, 0);

    for(int i = 0; i < n; i++){
        if(a[i] != b[i]){
            paritas[i] = 1;
        }
    }

    int valasz = 1;
    for(int i = 1; i < n; i++){
        if(paritas[i] != paritas[i - 1]){
            valasz++;
        }
    }

    cout << valasz << "\n";
}