#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;

class HUGE
{
private:
    int x[1000000];
public:
    HUGE()
    {
        memset(x,0,sizeof(x));
        x[0]=1;
    }
    HUGE(char a[])
    {
        memset(x,0,sizeof(x));
        x[0]=strlen(a);
        for(int i=1,j=x[0]-1; i<=x[0]; i++,j--)
            x[i]=a[j]-'0';
    }
    HUGE(long long n)
    {
        memset(x,0,sizeof(x));
        do
        {
            x[++x[0]]=n%10;
            n/=10;
        }
        while(n!=0);
    }

    void print()
    {
        for(int i=x[0]; i>=1; i--)
            printf("%d",x[i]);
        printf("\n");
    }
    HUGE& operator+(const HUGE &other)
    {
        HUGE rez;
        int i,tr;
        rez.x[0]=max(x[0],other.x[0]);
        tr=0;
        for(i=1; i<=x[0]; i++)
        {
            rez.x[i]=x[i]+other.x[i]+tr;
            tr=rez.x[i]/10;
            rez.x[i]%=10;
        }
        if(tr>0)
            rez.x[0]++,rez.x[rez.x[0]]=tr;
        return rez;
    }
    long long operator%(long long k)
    {
        long long r=0,i;
        for(i=x[0]; i>0; i--)
        {
            r=r*10+x[i];
            r%=k;
        }
        return r;
    }
};
char s[1000000];
int main()
{
    freopen("next.in","r",stdin);
    freopen("next.out","w",stdout);
    long long d;
    gets(s);
    HUGE n(s);
    scanf("%lld",&d);
    HUGE x(d-n%d);
    n=n+x;
    n.print();
    return 0;
}