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

# define  _fin	"next.in"
# define  _fout "next.out"

# define  maxn	1000001


short n[maxn], ad[maxn];
long long d, r;
char  buf[maxn];
int   i;

void add(short a[], short b[])
{
	short i, t=0;
	for (i=1; i<=a[0]||i<=b[0]||t; i++, t/=10)
		a[i] = ( t += (a[i]+b[i]) ) % 10;
	a[0]=i-1;
}

long long mod(short a[], long long b)
{
	int i;
	long long t=0;
	for(i=a[0]; i>0; i--)
		t = ( t*10 + a[i] ) % b;
	return t;
}

int main()
{
	freopen(_fin, "r", stdin);
	freopen(_fout,"w", stdout);
	scanf("%s\n%lld", buf, &d);
	for (i=strlen(buf)-1; i>=0; i--) n[++n[0]]=buf[i]-0x30;
	r = mod(n, d);
	if ( r ) {
		d=d-r;
		while ( d ) ad[++ad[0]]=short(d%10), d/=10;
		add(n, ad);
	}
	
	for (i=n[0]; i>=1; i--) printf("%d", n[i]);
	printf("\n");
	
	return 0;
}