#include <algorithm>
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ull unsigned long long
#define ld long double
#define ff first
#define ss second
#define ln "\n"
#define mp make_pair
#define pb push_back
#define INF (ll)2e18
#define MOD 998244353
ll get(ll n, string a, string b){
vector<ll> pz(n), po(n), pi(n), pd(n);
for (ll i=0; i<n; i++){
if (a[i]!=b[i]) pd[i]++;
if (i) pd[i]+=pd[i-1];
if (i==0 or b[i]!=b[i-1]){
if (b[i]=='1') pz[i]++;
else po[i]++;
}
if (a[i]==b[i] and (i==0 or a[i-1]!=b[i-1])){
pi[i]++;
}
if (i) {
pz[i]+=pz[i-1]; po[i]+=po[i-1];
pi[i]+=pi[i-1];
}
}
vector<vector<ll>> dp(n, vector<ll>(4, INF));
ll mn0 = 1, mn1=1, mn2=1, mn4=0;
for (ll i=0; i<n; i++){
dp[i][0] = mn0+pz[i];
dp[i][1] = mn1+po[i];
dp[i][2] = mn2+pi[i];
dp[i][3] = mn4+pd[i];
// cout << i << ": " << dp[i][0] << " - " << dp[i][1] << " - " << dp[i][2] << " - " << dp[i][3] << " |- " << pz[i] << " " << po[i] << " " << pi[i] << ln;
if (i+1<n){
mn0 = min({mn0, dp[i][0]-pz[i], dp[i][1]-pz[i]+1, dp[i][2]-pz[i]+1, dp[i][3]-pz[i]+1});
mn1 = min({mn1, dp[i][1]-po[i], dp[i][0]-po[i]+1, dp[i][2]-po[i]+1, dp[i][3]-po[i]+1});
mn2 = min({mn2, dp[i][2]-pi[i], dp[i][1]-pi[i]+1, dp[i][0]-pi[i]+1, dp[i][3]-pi[i]+1});
mn4 = min({mn4, dp[i][0]-pd[i], dp[i][1]-pd[i], dp[i][2]-pd[i], dp[i][3]-pd[i]});
}
}
return min({dp[n-1][0], dp[n-1][1], dp[n-1][2], dp[n-1][3]});
}
void solve(){
ll n; string a, b; cin >> n >> a >> b;
ll res=get(n, a, b);
for (auto &ch:a){
ch^=('1'^'0');
}
// cout << a << " -&- " << b << ln;
// cout << get(n, a, b)+1 << ln;
res=min(res, get(n, a, b)+1);
cout << res << ln;
}
int main(){
ios_base::sync_with_stdio(false); cin.tie(nullptr);
#ifdef LOCAL
auto start = chrono::high_resolution_clock::now();
#endif
ll t=1;
// cin >> t;
while (t--) solve();
#ifdef LOCAL
auto duration = chrono::duration_cast<chrono::microseconds>(chrono::high_resolution_clock::now() - start);
cout << setprecision(0) << fixed << "time: " << (double)duration.count()/1000.0 << " milliseconds" << endl;
#endif
}
