#include "bits/stdc++.h"
#define forr(_a,_b,_c) for(int _a = (_b); _a <= (_c); ++_a)
#define ford(_a,_b,_c) for(int _a = (_b) + 1; _a --> (_c);)
#define forf(_a,_b,_c) for(int _a = (_b); _a < (_c); ++_a)
#define st first
#define nd second
#define ll long long
#define ull unsigned long long
#define pii pair <int,int>
#define pll pair <ll,ll>
#define piii pair <int,pii>
#define vi vector <int>
#define pb push_back
#define mp make_pair
#define all(x) begin(x),end(x)
#define mask(i) (1LL << (i))
#define bit(x, i) (((x) >> (i)) & 1)
#define bp __builtin_popcountll
#define file "test"
using namespace std;
const int N = 1e6 + 5;
const int mod = 1e9 + 7; // 998244353
const ll oo = 1e18;
int n;
int a[N], b[N];
int dp[N][3][2];
void to_nho_cau() {
cin >> n;
int dem1 = 0, dem0 = 0;
forr(i, 1, n) {
char x; cin >> x;
a[i] = (x == '1') ? 1: 0;
}
forr(i, 1, n) {
char x; cin >> x;
b[i] = (x == '1') ? 1: 0;
}
memset(dp, 0x3f, sizeof dp);
dp[0][0][0] = 0;
forr(i, 1, n) {
forr(j, 0, 2) {
forr(k, 0, 1) {
//j = 0 là giữ nguyên giá trị ban đầu
// = 1 là chuyển thành 0
// = 2 là chuyển thành 1
//k = 0 nghĩa là đảo tại vị trí này
int val = a[i];
if(j == 1) val = 0;
if(j == 2) val = 1;
if(k == 1) val ^= 1;
if(val != b[i]) continue;
forr(j2, 0, 2) {
forr(k2, 0, 1) {
dp[i][j][k] = min(dp[i][j][k], dp[i-1][j2][k2] + (j > 0 && j != j2) + (k > 0 && k != k2));
}
}
}
}
}
int ans = mod;
forr(j, 0, 2) {
forr(k, 0, 1) {
ans = min(ans, dp[n][j][k]);
}
}
cout << ans << "\n";
}
signed main(){
ios_base::sync_with_stdio(0);cin.tie(0);
#ifdef LOCAL
freopen(file".inp","r",stdin);
freopen(file".out","w",stdout);
#endif
int t = 1;
//cin >> t;
while(t--) to_nho_cau();
}
