#pragma GCC target("avx")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
using namespace std;
int main() {
    int N;
    string S, T;
    cin >> N >> S >> T;
    int x = 0, y = 0;
    for( int i = 0; i < N; i++ ) {
        if( S[i] != T[i] ) {
            x++;
        }
    }
    reverse(S.begin(), S.end());
    for( int i = 0; i < N; i++ ) {
        if( S[i] != T[i] ) {
            y++;
        }
    }
    cout << min(x+(x&1)*N, y+(~y&1)*N) << endl;
}