#include <stdio.h>
#include <string.h>
int n[1000009];
short int rest[1000009];
char m[1000009];
long long  mod(int A[], long long B)
{
      long long i, t = 0;
      for (i = A[0]; i > 0; i--)
              t = (t * 10 + A[i]) % B;
      return t;
}
void add(int A[], short int B[])
{
      int 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;
}
int main(){
	int i;
	long long d,r;
	freopen("next.in","r",stdin);
	freopen("next.out","w",stdout);
	scanf("%s\n",m);
	scanf("%lld",&d);
	n[0]=strlen(m);
	for(i=1;i<=n[0];i++)
		n[i]=m[n[0]-i]-'0';
	r=mod(n,d);
	if(r==0)
		for(i=n[0];i>=1;i--)
			printf("%d",n[i]);
	else {
		r=d-r;
		while(r){
			rest[++rest[0]]=r%10;
			r/=10;
		}
		add(n,rest);
		for(i=n[0];i>=1;i--)
			printf("%d",n[i]);
	}
	return 0;
}