#include<fstream>
#include<string.h>
#define N 1000005

using namespace std;

char sir[N];
int rst[N], ok, nr[N];
long long d;

void add(int A[N], int B[N])
{
      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;
}

long long mod(int A[N], long long B)
{
      long long 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");

	  int lung, i;

      f.get(sir, N-1);
	  lung = strlen(sir);
	  for(i = 0; i < lung; i++)
		nr[lung-i] = sir[i]-'0';
	  nr[0] = lung;
      f.get();
	  f>>d;
      long long r = mod(nr,d);
	  r = (d - r)%d;
	  
      while(r)
	  {
	     rst[++rst[0]] = r%10;
		 r/= 10;
      }

      add(nr, rst);

	  for(i = nr[0]; i >= 1; i--)
		g<<nr[i];

	  return 0;
}