#include <fstream>
#include <algorithm>
using namespace std;
long long n,k,rez,c,p,j,a,x,i,d,exp;
long long f[10000];
ifstream cin("factoriale.in");
ofstream cout("factoriale.out");
int main () {
    cin>>n>>k;
    rez=1;
    for (i=1;i<=n;i++) {
        cin>>a;
        for (j=1;j<=a;j++) {
            x=j;
            d=2;
            while (x>1) {
                while (x%d==0) {
                    f[d]++;
                    x/=d;
                }
                d++;
                if (x>1&&d*d>x) {
                    d=x;
                }
            }
        }
    }
        for (i=2;i<=97;i++) {
            if (f[i]>0) {
                exp=k-f[i]%k;
                if (f[i]-k==k) {
                    exp=0;
                }
                p=1;
                for (j=1;j<=exp;j++) {
                    p*=i;
                }
                rez*=p;
            }
        }
    cout<<rez;
}