Solution

#include <iostream>
#include <string>
using namespace std;
using ll = long long;

int main() {
	//freopen("breedflip.in", "r", stdin);
	//freopen("breedflip.out", "w", stdout);
	ll n;
	cin >> n;
	string A;
	string B;
	cin >> A >> B;
	ll ans = 0;
	bool mismatched = false;
	for (ll i = 0; i < n; i++) {
		if (A[i] != B[i]) {
			if (!mismatched) {
				mismatched = true;
				ans++;
			}
		} else {
			mismatched = false;
		}
	}
	cout << ans << endl;
}