#include<stdio.h>
#include<string.h>
FILE*f=fopen("next.in","r");
FILE*g=fopen("next.out","w");
long d,r,p;
char x[1000006];
int a[1000006];
void read()
        {
        fscanf(f,"%s",x);
        long i;
         a[0]=strlen(x);
         for(i=0;i<a[0];++i)
                {
                a[a[0]-i]=x[i]-'0';
                }
       fscanf(f,"%ld",&d);
       }
int mod(int A[], int B)
 {
 long i, t = 0;
 for (i = A[0]; i > 0; i--)
        t = (t * 10 + A[i]) % B;
 return t;
  }
void add()
        {
        int i,t=0,c;
        i=1;
        while(i<=a[0]||d!=0)
                {
                c=a[i];
                a[i]=(a[i]+t+d%10)%10;
                t=(c+d%10+t)/10;
                d/=10;
                i++;
                }
       if(t) a[++a[0]]=t;
       }
int main()
        {
        read();
        long i;
        r=mod(a,d);
        d=(d-r)%d;
        add();
        for(i=a[0];i>=1;--i) fprintf(g,"%d",a[i]);
        return 0;
        }