#include<iostream>
#include<fstream>
#include<string.h>
using namespace std;
int baza;
class huge 
{
	public: int v[100001];
	int i,aux;
	huge() 
	{
		for(i=0;i<=100000;i++)
			v[i]=0;
	}
	inline void operator = (huge a)
	{
		memcpy (v,a.v,sizeof (a.v));
	}
	inline void operator = (int a)
	{
		memset(v,0,sizeof(v));
		for ( ;a>0;a=a/baza) 
			v[++v[0]]=a%baza;
	}
	inline huge operator + (huge &a) const
	{
		huge b; 
		int i,t;
		t=0;
		for(i=1;i<=a.v[0]||i<=v[0]||t;i++,t=t/baza) {
			t=t+a.v[i]+v[i];
			b.v[i]=t%baza;
		}
		b.v[0]=i-1;
		return b;
	}
	inline huge operator - (long long a)
	{
		huge b; 
		long long i,t;
		t=a;
		memcpy (b.v,v,sizeof (v));
        for (i=1;t;++i,t/=baza) {
            b.v[i]=b.v[i]-(t%baza);
            if(b.v[i]<0) {
				b.v[i+1]--;
				b.v[i]=b.v[i]+baza;
			}
        }
        for ( ;b.v[0]>1 && !b.v[b.v[0]]; b.v[0]--);
        return b;
	}

	inline long long operator % (long long b) const
	{
		int i;
		long long t;
		t=0;
		for (i=v[0];i>=1;i--)
			t=(t*baza+v[i])%b;
		return t;
	}
	friend ifstream& operator >> (ifstream &f, huge &a)
	{
		int l;
	    char c[1000001];
		memset(c,0,sizeof(0));
	    f>>c; 
		l=strlen(c);
	    for (int i=l-1; i>=0; i=i-4) {
	        a.v[++a.v[0]]=c[i]-48;
	        if(i>0) 
				a.v[a.v[0]]=a.v[a.v[0]]+((c[i-1]-48)*10);
	        if(i>1) 
				a.v[a.v[0]]=a.v[a.v[0]]+((c[i-2]-48)*100);
	        if(i>2) 
				a.v[a.v[0]]=a.v[a.v[0]]+((c[i-3]-48)*1000);
	    }
	    return f;
	}
	friend ofstream& operator << (ofstream &g, huge &a)
	{
		int x,i;
		g<<a.v[a.v[0]];
		for (i=a.v[0]-1;i>=1;i--) {
			if (a.v[i]==0) {
				for (x=1;x<baza;x=x*10) 
					g<<"0";
				continue;
			}
			for (x=a.v[i]*10;x<baza;x=x*10) 
				g<<"0";
			g<<a.v[i];
		}
		return g;
	}
};
huge n,dd;
long long d;
int main ()
{
	long long rest;
	baza=10000;
	ifstream f("next.in");
	ofstream g("next.out");
	f>>n>>d;
	f.close();
	dd=d;
	if(n%d!=0) {
		cout<<n%d;
		rest=d-(n%d);
		dd=rest;
		n=n+dd;
	}
	g<<n;
	g.close();
	return 0;
}