#include <iostream>
#include <fstream>
#include <string.h>
#define Nmax 1000000
typedef unsigned int Huge[Nmax+1];

using namespace std;

Huge n;
long long int d;

unsigned long long int Mod(Huge A, unsigned long long int X)
{
    /* Intoarce A%X */
    int i;
    unsigned long R=0;
    for (i=A[0]; i; i--)
        R=(10*R+A[i])%X;
    return R;
}

int main()
{
    ifstream fin ("next.in");
    ofstream fout ("next.out");
    char cit[1000001];
    long long int rest;
    fin.getline(cit,1000001);
    n[0]=strlen(cit);
    for (int i=n[0]-1; i>=0; i--)
        n[n[0]-i]=cit[i]-'0';
    fin>>d;
    rest=Mod(n,d);
    if (rest==0)
        fout<<cit;
    else
    {
        unsigned long long int adun=d-rest;
        int T=0;
        n[1]+=adun;
        for (int i=1; i<=n[0]; i++)
        {
            n[i]+=T;
            T=n[i]/10;
            n[i]%=10;
        }
        if (T) n[++n[0]]=T;
        for (int i=n[0]; i>=1; i--)
            fout<<n[i];
    }
    return 0;
}