#include<fstream.h>
//using namespace std;
ifstream f1 ("next.in");
ofstream f2 ("next.out");
int v2[1001],vf[1000001];
char v[1000001];
long long mod(int vf[1000001], long long b)
{
      long long i;
      long long t = 0;
      for (i = vf[0]; i>0; i--)
	t = (t*10 + vf[i]) % b;
      return t;}
void suma()
 {
       long long i, t = 0;
       for (i=1; i<=vf[0] || i<=v2[0] || t; i++, t/=10)
	  {
	  if (i<=v2[0]) vf[i] = (t +=vf[i]+v2[i])%10;
            else vf[i]=(t+=vf[i])%10;
           }
       vf[0]=i-1;
}  
int main()
{

   long long i,j;
   long long d,t,x;
   char c;
   i=0;
   while (f1.get(c) && int(c)>=48) {i++; v[i]=c;}
    for (j=1; j<=i; j++) vf[j]=int(v[i-j+1])-48;
   vf[0]=i;
   f1>>d;
   t=mod(vf,d);
   t=(d-t)%d;
   x=v[0];
   i=0;
   while (t!=0) {i++; v2[i]=t%10; t/=10;}
   v2[0]=i;
   suma();
   for (i=vf[0]; i>=1; i--) f2<<vf[i];
   return 0;
}