#include<fstream>
#include<string>
using namespace std;

string s;
long long d,r;


int main()
{
   ifstream cin("next.in");
   ofstream cout("next.out");


   cin>>s;
   cin>>d;
   for (int i=0;i<s.size();i++)
    r=(r*10+s[i]-'0')%d;
   d-=r;

   for (int i=s.size()-1;i>=0;i--){
    d+=s[i]-'0'; cout<<d%10;
    d/=10;
   }
   return 0;
}