#include <stdio.h>
#include <cstring>

#define dim 1000001

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

void add(int A[], long long unsigned B)
{
      int i, t = 0;
      
      long long unsigned s = B;
      
      for (i=1; i<=A[0] || t; i++)
      {
             s += A[i] ;   
             A[i] = s%10;
             s /= 10;
      }       
      A[0] = i - 1;
}

void tipar (int A[])
{
     int i;
     for( i = A[0]; i; -- i)
          printf("%d", A[i]);
}

long long unsigned  D;
int A[dim];

char Nr[dim];

int main()
{

   freopen("next.in","r",stdin);
   freopen("next.out","w",stdout);

   scanf("%s", Nr);
   scanf("%llu", &D);
   
   long long unsigned i, n = strlen(Nr);
   
   A[0] = n;
   
   for ( i = 1; i <= n; ++ i)
       A[i] = Nr[n-i] - '0'; 
   
   long long unsigned rest = mod(A, D);
     
//   tipar(A);  
      
//   printf ("\n%llu\n",(D-rest) % D);   
   
   add(A, (D-rest) % D);   
      
   tipar(A);
   
   return 0;
}