#include <fstream>
using namespace std;

#define MAX 1000001

ifstream f("next.in");
ofstream g("next.out");

int N[MAX],T[20];
char n[MAX];
long long D,J,k;

void add(int A[], int B[])
{
    int i, t = 0;
    for (i=1; i<= B[0] + 1 || t; i++, t/=10)
        A[i] = (t += A[i] + B[i]) % 10;
}
long long mod(int A[], long long B)
{
      int i;
      long long t=0;
      for (i = A[0]; i > 0; i--)
              t = (long long) (t * 10 + A[i]) % B;
      return t;
}
void citire(int x[],char a[])
{
    x[0]=strlen(a);
    for (int  i = x[0] -1; i >= 0; --i )
        x[i+1]=a[x[0]-i-1] - '0';
}
void afis(int x[])
{
    for (int i=x[0];i>0;i--) g<<x[i];
}
int main()
{
     f>>n;
     f>>D;
     citire(N,n);
     k = mod(N,D);
     J=D-k;
     k = J % D;
     sprintf( n, "%lld", k );
     citire(T,n);
     add(N,T);
     afis(N);
     return 0;
}