#include <cstdio>
#define MAXN 1000000
int v[MAXN+1];
int main(){
   FILE*fi,*fout;
   int aux,b,e,i,n;
   long long d,nr,t;
   char a;
   fi=fopen("next.in" ,"r");
   fout=fopen("next.out" ,"w");
   a=fgetc(fi);
   n=0;
   while(a>='0'&&a<='9'){
      v[n++]=a-'0';
      a=fgetc(fi);
   }
   fscanf(fi,"%lld" ,&d);
   nr=0;
   for(i=0;i<n;i++){
       nr=nr*10+v[i];
       nr%=d;
   }
   b=0;
   e=n-1;
   while(b<e){
      aux=v[b];
      v[b]=v[e];
      v[e]=aux;
      b++;
      e--;
   }
   nr=d-nr;
   i=0;
   t=nr;
   while(i<n||t>0){
      t=t+v[i];
      v[i]=t%10;
      t/=10;
      i++;
   }
   i--;
   while(i>=0){
      fprintf(fout,"%d" ,v[i]);
      i--;
   }
   fclose(fi);
   fclose(fout);
   return 0;
}