#include <bits/stdc++.h>
using namespace std;
int gcd(int a, int b) {
  if (a == 0) return b;
  return gcd(b % a, a);
}
long long int power(long long int x, long long int y, long long int p) {
  long long int res = 1;
  x = x % p;
  while (y > 0) {
    if (y & 1) res = (res * x) % p;
    y = y >> 1;
    x = (x * x) % p;
  }
  return res;
}
int main() {
  int n;
  cin >> n;
  long long int n1 = 0, n0 = 0, x1 = 0, x0 = 0;
  string a, b;
  cin >> a >> b;
  for (int i = 0; i < n; i++) {
    if (a[i] == '0' && b[i] == '1') n0++;
    if (a[i] == '1' && b[i] == '1') n1++;
    if (a[i] == '1' && b[i] == '0') x1++;
    if (a[i] == '0' && b[i] == '0') x0++;
  }
  long long int ans = 0;
  for (int i = 0; i < n; i++) {
    if (b[i] == '0') {
      if (a[i] == '1')
        ans += n0;
      else
        ans += n1;
    }
  }
  ans += x1 * x0;
  cout << ans;
  return 0;
}
