#include <fstream.h>
#include <math.h>

ifstream fin("factoriale.in");
ofstream fout ("factoriale.out");

int a[200];
int x[200],n,k;

void citire()
{
   fin>>n>>k;
     for (int i=0;i<n;i++)
	fin>>x[i];
   fin.close();
}

void pro()
{
   for (int i=0;i<n;i++)
   {
      int aux1=x[i];
      for  (int au=2;au<=aux1;au++)
      {
	int aux=au;
      while (aux%2==0)
      {
	aux/=2;
	a[2]++;
      }
      for (int d=3;d<aux/d;d+=2)
	 while (aux%d==0)
	 {
	   aux/=d;
	   a[d]++;
	 }
      if (aux!=1)
	 a[aux]++;
      }
   }
}

void afisare()
{
   long long S=1;
   for (int i=0;i<100;i++)
	if (a[i]!=0 && a[i]<k)
	    S=pow(i,k-a[i]);
   fout<<S<<"\n";
}

int main ()
{
  citire();
  pro();
  afisare();
  fout.close();
  return 0;
}