732A - Buy a Shovel

#include<bits/stdc++.h>

using namespace std;

int main()

{

  int n,r;

  int svl=0;

  cin>>n>>r;

  int base=n;

  while(1)

  {

      if(n%10!=0)

      {

          svl++;

      }

      if(n%10==r)

      {

          break;

      }

      if(n%10==0)

      {

          svl++;

          break;

      }

      n +=base;

  }

  cout<<svl<<endl;

}