#include <fstream>
#include <cstring>
using namespace std;

short int N[1000005], R[16];
long long int D;
char X[1000005];

int main()
{
    ifstream fin("next.in");
    ofstream fout("next.out");
    
    long long int rest = 0;
    int i;
    fin >> X;
    fin >> D;
    N[0] = strlen(X);
    for (i = 0; i < N[0]; i++)
        N[N[0]-i] = X[i] - '0';
    
    for (i = N[0]; i > 0; i--)  
        rest = (rest * 10 + N[i]) % D;
  
   /* if (rest)
    {*/
          rest = D - rest;
          rest %= D;
          while (rest)
          {
                R[++R[0]] = rest%10;
                rest /= 10;
          }
          rest = 0;
          for (i = 1; i <= N[0] || i <= R[0] || rest; i++, rest/=10)  
               N[i] = (rest += N[i] + R[i]) % 10;  
          N[0] = i - 1;  
//    }
    
    for (i = N[0]; i > 0; i--)
        fout << N[i];
    fout << "\n";
    
    fin.close();
    fout.close();
    return 0;
}