#include<fstream>
#include <bitset>
using namespace std;
ifstream cin("frac.in");
ofstream cout("frac.out");
#define INFINIT 12000000000
bitset <INFINIT>  prime;

   

void fa(long long k)
   {
            long long i;
            i=k;
            while (i<INFINIT)
            {
            prime[i]=1;
            i=i+k;
            }
}       
int main()
{   long long n, nr, i,d=2;
    cin>>n>>nr;
    while (n>1)
    {
            if (n%d==0) {fa(d);
                           while (n%d==0) n=n/d;
                           }
            d++;
            }
long long nr_frac=0;
i=0;
while(nr_frac<nr)
   {i++;
                 if (prime[i]==0) nr_frac++;
   }
   cout<<i;
   
return 0;
}