#include <bits/stdc++.h>   using namespace std;   inline long long getnum() {     char c = getchar();     long long num, sign = 1;     for (; c <  0  || c >  9 ; c = getchar())       if (c ==  - ) sign = -1;     for (num = 0; c >=  0  && c <=  9 ;) {       c -=  0 ;       num = num * 10 + c;       c = getchar();     }     return num * sign;   }   int main() {     int n = getnum(), m = getnum();     int ans = 0;     while (1) {       if ((ans * n) % 10 == 0 && ans > 0) {         cout << ans;         return 0;       }       if ((ans * n - m) % 10 == 0) {         cout << ans;         return 0;       }       ans++;     }   }   