#include<fstream>
using namespace std;
ifstream f("next.in");
ofstream g("next.out");
int i,n;
char ch;
unsigned long long m,y,t,a[1000001];
int main()
{f.get(ch);
while(ch!='\n')
{++n;
a[n]=ch-48;
f.get(ch);
}
f>>m;
t=0;
for(i=1;i<=n;++i)
	t=(t*10+a[i])%m;
t=m-t;
for(i=n;i>=1;--i)
{y=t+a[i];
a[i]=y%10;
t=y/10;
}
if(t)
	g<<t;
for(i=1;i<=n;++i)
	g<<a[i];
g<<'\n';
return 0;
}