#include<fstream>

using namespace std;

int n,p,c=1,a[100],k,z;
int main()
{
    ifstream fin("frac.in");
    ofstream fout("frac.out");
int i,j,cont=0;
fin>>n>>p;
for(j = 2;j <= n/2; j++)
if(n%j == 0)
a[k++] = j;
    for(i = 2;;i++)
    {
       for(j = 0; j < k; j++)
        {
        if(i%a[j] != 0)
        cont =1;
        else
        {
        cont = 0;
        break;
        }
    }    
        if(cont == 1)
            {
            c++;
            z=i;
            }    
            
            if(c == p)
            break;    
}
fout<<z;

fin.close();
fout.close();

return 0;

}