#include <cstdio>
#include <algorithm>
#define MAX 2000000
using namespace std;
 
typedef int B[1000005];
B rez;
char f[MAX];
int D,t,pos=0,MOD=0;
void Return(B arr, int nr)
{
	int t=0;
      for(int i=arr[0];i>0;i--)
	  {
		t=t*10+arr[i];
		if(t/nr>0)
			t%=nr;
	  }
	  MOD=t;
}
void Sum(B &s,int nr)
{
    int t=nr,i=1;
	while(t+s[i]>9||t>0)
	{
		s[i]+=t;
		t=s[i]/10;
		s[i]%=10;
		if(i==s[0]&t>0)
			s[0]++;
		i++;
	}
}
int main()
{
    freopen("next.in","r",stdin);
    freopen("next.out","w",stdout);
 
    fread(f,1,MAX,stdin);
    while(f[pos]>='0'&&f[pos]<='9')
        rez[++rez[0]]=f[pos++]-'0';
 
    for(int i=1;i<=rez[0]/2;i++)
    {
        t=rez[i];
        rez[i]=rez[rez[0]-i+1];
        rez[rez[0]-i+1]=t;
    }
    pos++;
    while(f[pos]>='0'&&f[pos]<='9')
        D=D*10+f[pos++]-'0';
    Return(rez,D);
	if(MOD>0)Sum(rez,D-MOD);
    for(int i=rez[0];i>0;i--)
        printf("%d",rez[i]);
    return 0;
}