#include <bits/stdc++.h>
using namespace std;
string itosm(long long x) {
  if (x == 0) return "0";
  string res = "";
  while (x > 0) {
    res += ((x % 10) + '0');
    x /= 10;
  }
  reverse(res.begin(), res.end());
  return res;
}
long long stoim(string str) {
  long long res = 0;
  int p = 0;
  if (str[0] == '-') p++;
  for (int i = p; i < str.length(); i++) {
    res *= 10;
    res += (str[i] - '0');
  }
  return res;
}
const long long infll = 1e18 + 3;
const int inf = 1009000999;
const long double eps = 1e-7;
const int maxn = 1e6 + 1146;
const int baseint = 1000200013;
const long long basell = 1e18 + 3;
const long double PI = acos(-1.0);
const long long mod = 1e9 + 9;
void solve() {
  int n;
  cin >> n;
  string a, b;
  cin >> a >> b;
  long long c1 = 0, c2 = 0, c3 = 0, c4 = 0;
  for (int i = 0; i < n; i++) {
    if (a[i] == '0' && b[i] == '0') c1++;
    if (a[i] == '0' && b[i] == '1') c2++;
    if (a[i] == '1' && b[i] == '0') c3++;
    if (a[i] == '1' && b[i] == '1') c4++;
  }
  cout << c1 * (c3 + c4) + c3 * c2;
}
int main() {
  srand(time(0));
  ios_base::sync_with_stdio(0);
  ;
  cin.tie(0);
  cout.tie(0);
  solve();
  return 0;
}
