#include <fstream>
#include <cstring>
#include <algorithm>

using namespace std;

ifstream cin("next.in");
ofstream cout("next.out");

const int NMAX=1000005;

void adun_h_h(int a[],int b[],int c[NMAX]) {
    int i,tr=0,aux;
    c[0]=max(a[0],b[0]);
    for(i=1; i<=c[0]; i++) {
        aux=a[i]+b[i]+tr;
        c[i]=aux%10;
        tr=aux/10;
    }
    if(tr==1)
        c[++c[0]]=tr;
}
int div_h_int(int a[],int k) {
    int i,r;
    r=0;
    for(i=a[0]; i>=1; i--) {
        r=r*10+a[i];
        r=r%k;
    }
    return r;
}
int main() {
    char ch;
    long long int d,r;
    int m,k,a[NMAX+5],c[NMAX+5],b[25];
    memset(c,0,sizeof(c));
    memset(a,0,sizeof(a));
    ch=cin.get();
    while(ch!='\n') {
        if(ch>='0' && ch<='9')
            a[++a[0]]=ch-'0';
        ch=cin.get();
    }
    reverse(a+1,a+a[0]+1);
    cin>>d;
    r=div_h_int(a,d);
    if(r==0) {
        for(int i=a[0]; i>=1; i--)cout<<a[i];
    } else {
        r=d-r;
        memset(b,0,sizeof(b));
        do {
            b[++b[0]]=r%10;
            r/=10;
        } while(r>0);
        adun_h_h(a,b,c);
        for(int i=c[0]; i>=1; i--) {
            cout<<c[i];
        }
    }
    return 0;
}