#include <fstream>
#include <string.h>
#include <algorithm>
using namespace std;
ifstream f("next.in");
ofstream g("next.out");
long long D;
int N[1000002],V[18],N2[1000002];
char Aux[1000002];
void reverse(int first,int last)
{
    while ((first!=last)&&(first!=--last)) {
        swap (N[first],N[last]);
        ++first;
    }
}
void Read()
{
    f.getline(Aux,1000000);
    int i=0;
    while(Aux[i]!=0)
    {
        N[i+1]=Aux[i]-'0';
        N[0]++;
        i++;
    }
    for(i=1;i<=N[0];i++)
        N2[N[0]-i+1]=N[i];
    N2[0]=N[0];
    f>>D;
}
void add(int A[], int B[])
{
      int i, t = 0;
      for (i=1; i<=A[0] || i<=B[0] || t; i++, t/=10)
              A[i] = (t += A[i] + B[i]) % 10;
      A[0] = i - 1;
}
void AtribValue(int H[], long long X) {
  H[0] = 0;
  while (X) {
      ++H[0];
      H[H[0]] = X % 10;
      X /= 10;
  }
}
long long Mod(int A[],long long X)
/* Intoarce A%X */
{ int i;
  unsigned long R=0;

  for (i=A[0];i;i--)
    R=(10*R+A[i])%X;
  return R;
}
void Solve()
{
    long long Rest=Mod(N2,D);
    AtribValue(V,D-Rest);
    add(N2,V);
    for(int i=N2[0];i>=1;i--)
        g<<N2[i];
    g<<"\n";
}
int main()
{
    Read();
    Solve();
    return 0;
}