#include <bits/stdc++.h>   using namespace std;   void fact(int n) {     const int N = 1e5;     vector<int> arr(N, 0);     int q = 2;     arr[0] = 1;     int len = 1;     int x = 0;     int carry = 0;     while (q <= n) {       x = 0;       carry = 0;       while (x < len) {         arr[x] = arr[x] * q + carry;         carry = arr[x] / 10;         arr[x] = arr[x] % 10;         x++;       }       while (carry) {         arr[len] = carry % 10;         carry = carry / 10;         len++;       }       q++;     }     len--;     for (int i = len; i >= 0; i--) {       cout << arr[i];     }     return;   }   long long int binary_exp(long long int x, long long int n) {     if (n == 0) {       return 1;     } else if (n == 1) {       return x % 1000000007;     } else {       long long int temp = binary_exp(x, n / 2);       temp = (temp * temp) % 1000000007;       if (n % 2 == 0) {         return temp;       } else {         return ((x % 1000000007) * temp) % 1000000007;       }     }   }   int main() {     int k, r;     cin >> k >> r;     int i = 1;     while (i * k % 10 != r and i * k % 10 != 0) {       i++;     }     cout << i;     return 0;   }   