#include <stdio.h>
#include <string.h>

    long long d,i,l,nr,r;
    long n[1000002];
    char ch[1000002];

int main(){
    freopen("next.in","r",stdin);
    freopen("next.out","w",stdout);
    
    scanf("%s",ch);
    scanf("%lld",&d);
    
    nr=0;
    l=strlen(ch);
    for (i=0;i<l;i++)n[l-i]=ch[i]-'0';
    if (l<=16)for (i=0;i<l;i++)nr=(long long)nr*10+(ch[i]-'0');
    
    if ((nr&&nr>d)||l>=16){
       r=0;   
       for (i = 0; i < l; i++)   
              r= ((long long)r* 10 + ch[i]-'0') % d;   
       if (r){
          r=(long long)d-r;
          for (i=1;i<=l;i++){
              if(r){n[i]=(long long)n[i]+r%10;r=(long long)r/10;}
              if (n[i]>=10){n[i+1]=n[i+1]+n[i]/10;n[i]%=10;if(i==l)l++;}
          }
       }
       for (i=l;i>=1;i--)printf("%ld",n[i]);
       printf("\n");
    }
    else printf("%lld\n",d);
    
    return 0;
}