#include <bits/stdc++.h>
using namespace std;
string a, b;
int main() {
  int n;
  while (cin >> n) {
    cin >> a >> b;
    long long ans = 0;
    long long x = 0, y = 0, p = 0, q = 0;
    for (int i = 0; i < n; i++)
      if (b[i] == '1') a[i] == '0' ? x++ : y++;
    for (int i = 0; i < n; i++)
      if (b[i] == '0') a[i] == '0' ? p++ : q++;
    for (int i = 0; i < n; i++)
      if (b[i] == '0') a[i] == '0' ? ans += y : ans += x;
    ans += (long long)p * q;
    cout << ans << endl;
  }
  return 0;
}
