#include <stdio.h>
#include <string.h>

const int N=1000000;
char c[N-1];
int  c2[N-1];
int e[N-1];
long long d,rest=0;

void obtinere(FILE *f1)
{
	int  i,nr=1;
	fgets(c,N-1,f1);
	c2[0]=strlen(c)-1;
	for(i=c2[0]-1;i>=0;i--)
		c2[nr++]=c[i]-'0';
	fscanf(f1,"%lld",&d);
	
}
void restimpartire()
{
	int i,t=0;
	for(i=c2[0];i>0;i--)
		rest=(t=t*10+c2[i])%d;
	
}
void vector()
{
	long long a,nr=1;
	a=d;
	e[0]=0;
	while(a)
	{
		e[0]++;
		e[nr++]=a%10;
		a=a/10;
	}

}
void suma()
{
	int i,t=0;
	for(i=1;i<=c2[0] || i<=e[0] || t;i++,t=t/10)
	{
		t=t+c2[i]+e[i];
		c2[i]=t%10;
	}

}
	
int main()
{
	int i;
	FILE *f1,*f2;
	f1=fopen("next.in","r");
	f2=fopen("next.out","w");
	obtinere(f1);
	restimpartire();
	if(rest==0)
		for(i=c2[0];i>=1;i--)
			fprintf(f2,"%d",c2[i]);
	else
	{
		d=d-rest;
		vector();
		suma();
		for(i=c2[0];i>=1;i--)
			fprintf(f2,"%d",c2[i]);
	}
	return 0;
}