#include <bits/stdc++.h>
using namespace std;
bool isPrime(int n) {
  if (n <= 3) {
    return true;
  }
  if (n % 2 == 0 || n % 3 == 0) return false;
  for (int i = 5; i * i <= n; i = i + 6)
    if (n % i == 0 || n % (i + 2) == 0) return false;
  return true;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  int n, k;
  cin >> n >> k;
  int i = 1;
  int sum;
  while (1) {
    sum = n * i;
    if (sum % 10 == k || sum % 10 == 0) {
      break;
    }
    i++;
  }
  cout << i;
  return 0;
}
