#include <stdio.h>
#include <string.h>
#define M 1000009 
char S[M];
short int H[M];
int N[M];
long long  D,R;
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()
{
	freopen("next.in", "r", stdin);
	freopen("next.out", "w", stdout);
	scanf("%s\n", S);
	scanf("%lld", &D);
	N[0]=strlen(S);
	for(int i=1;i<=N[0];++i)
		N[i]=(S[N[0]-i]-'0');
	R=mod(N,D);
	if(R>0)
	{
		R=D-R;
		while(R)
		{
			H[++H[0]]=R%10;
			R/=10;
		}	
		add(N,H);
	}
	for(int i=N[0];i>=1;--i)
		printf("%d", N[i]);
	return 0;
}