#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

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

    string indulas;
    string cel;
    int forditas = 0;

    cin >> indulas >> cel;

    for(int i = n - 1; i >= 0; i--) {
        if(forditas % 2 == 0 && indulas[i] != cel[i]) {
            forditas++;
        }
        if(forditas % 2 == 1 && indulas[i] == cel[i]) {
            forditas++;
        }
    }

    cout << forditas;

    return 0;
}