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

int a[10000001];
long long d;

long long Mod()
 { int i;
   long long R=0;
   for (i=a[0];i;i--)
     R=(10*R+a[i])%d;
   return R;
 }

void adun(long long R)
{   long nr=0;
    while(R!=0)
     {
        nr++;
        a[nr]=R%10+a[nr];
        long pz=nr;
        while(a[pz]>10)
         {a[pz+1]=a[pz+1]+1;
          a[pz]=a[pz]%10;
           pz++;
          }
        R/=10;
     }
    for(int i=a[0];i>=1;i--)
     printf("%d",a[i]);
    printf("\n");
}

void solve()
{
    long long R=Mod();
    adun((d-R)%d);
}

int main()
{
    freopen("next.in","r",stdin);
    freopen("next.out","w",stdout);
    char c[1000009];
    fgets(c,1000009,stdin);
    for(int i=strlen(c)-2;i>=0;i--)
      a[++a[0]]=c[i]-'0';
    scanf("%lld",&d);
    solve();
    return 0;
}