#include <bits/stdc++.h>
using namespace std;
long long int x_pow_y(long long int x, int y) {
  if (y == 0) return 1;
  long long int temp;
  temp = x_pow_y(x, y / 2);
  if (y % 2 == 0)
    return temp * temp;
  else
    return x * temp * temp;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long int n;
  string a, b;
  cin >> n;
  cin >> a;
  cin >> b;
  long long int count = 0;
  int x, y;
  for (int i = 0; i < n; i++) {
    x = a[i] - 48;
    y = b[i] - 48;
    int c = abs(x - y);
    if (c > 5) {
      x = min((a[i] - 48), (b[i] - 48));
      y = max((a[i] - 48), (b[i] - 48));
      int c1 = 0;
      while (y % 10 != x) {
        y++;
        c1++;
      }
      count += c1;
    } else
      count += c;
  }
  cout << count << "\n";
  return 0;
}
