#include <stdio.h>
#define Nmax 1000005
#define LL long long

int a[Nmax],i,ok,v[20];
char c;
LL D,t,aux;

void adun(int a[], int b[]){
	int i,t;
   for(i=1,t=0; 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);
   for(ok=1; ok;  ){
   	scanf("%c",&c);
      if( c !='\n' ) a[++a[0]]=c-'0';
      else ok=0;
   }
   scanf("%lld",&D);

 	// fac rest
   for(i=1,t=0;i<=a[0];++i)
   	t=( t*10 + a[i] ) % D;

   if(t == 0)
   	for(i=1;i<=a[0];++i) printf("%d",a[i]);
   else{
      for(i=1;i<=a[0]/2;++i){
      	aux=a[i]; a[i]=a[a[0]-i+1];
         a[a[0]-i+1]=aux;
      }
   	aux = D-t;
      while( aux > 0){ v[++v[0]]=aux % 10; aux = aux/10; }

      adun(a,v);

      for(i=a[0]; i>=1; --i) printf("%d",a[i]);
   }

   printf("\n");
   fclose(stdin); fclose(stdout);
   return 0;
}