#include<fstream>
#include<string.h>
#define N 1000000

using namespace std;

char sir[N];
int rst[20];
int ok, nr[N];
unsigned long long 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;
}

int mod(int A[], int B)
{
      int i, t = 0;
      for (i = A[0]; i > 0; i--)
              t = (t * 10 + A[i]) % B;
      return t;
}


int main()
{
          ifstream f("next.in");
          ofstream g("next.out");
          
          
          
	  f.getline(sir, 999999);
	  int lung  = strlen(sir), rest, k = 1;
	  for(int i = 0; i < strlen(sir); i++)
		nr[lung-i] = sir[i]-'0';
	  nr[0] = strlen(sir);

	  f>>d;

	  rest = d - mod(nr,d);

	  while(rest)
	  {
		rst[k++] = rest%10;
		rest/= 10;
	  }

	  rst[0] = k-1;

	  add(nr, rst);

	  for(int i = 1; i <= nr[0]; i++)
		g<<nr[i];

	  return 0;
}