#include <fstream.h>
long long v[2000005] ;
int main()
{ long long n,i,p,x,c=0,j;
ifstream f1("frac.in");
ofstream f2("frac.out");
f1>>n>>p;
for (i=2;i*i<=n;i++)
	if (n%i==0) v[i]=1;
for (i=2;i<=2000000;i++)
	if (v[i]==1)
		{
		j=2;
		while(i*j<=2000000)
			{
			v[i*j]=1;
			j++;
			}
		}
	else { c++;
		  if(c==p-1) {f2<<i; break;}
	}
	return 0;
}