#include<bits/stdc++.h>
using namespace std;
#include<atcoder/all>
using namespace atcoder;
using ll = long long;
int n;
string s,t;

void solve(){
	int ans = 0;
	for(int i = n-1;i>=0;i--){
		if(abs(s[i]-t[i])!=ans%2){
			ans++;
		}
	}
	cout<<ans<<endl;
}

signed main(){
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
	cin >> n >> s >> t;
	solve();
}