#include <bits/stdc++.h>

int read() {
    int x = 0, f = 1;
    char c = getchar();
    while (c < '0' || c > '9') { if (c == '-') f = -1; c = getchar(); }
    while (c >= '0' && c <= '9') { x = x * 10 + c - '0'; c = getchar(); }
    return x * f;
}

int main() {
    read();
    std::string s, t;
    std::cin >> s >> t;

    int ans = INT_MAX;
    for (int m : { 0, 1 }) {
        int cnt{};
        for (int i = 0; i < s.size(); i++) cnt += s[i] != t[i];
        if (cnt % 2== m) ans = std::min(ans, cnt);
        std::reverse(s.begin(), s.end());
    }
    std::cout << ans << '\n';

    return 0;
}