#include <fstream>
using namespace std;
ifstream cin("factoriale.in");
ofstream cout("factoriale.out");
long long f[105], x, cnt, d, nr, i, j, k, n, p;
int main(){
    cnt=1;
    cin>>n>>k;
    for(i=1;i<=n;i++){
        cin>>x;
        p=1;
        for(j=1;j<=x;j++){
            p=p*j;
        }
        d=2;
        while(p>1){
            while(p % d == 0){
                f[d]++;
                p /= d;
            }
            d++;
            if(p>1 && d * d > p){
                d = p;
            }
        }

    }
    for(i=2;i<=100;i++){
        if(f[i]!=0){
            nr=k-f[i];
            for(j=1;j<=nr;j++)
                cnt=cnt*i;
        }
    }
    cout<<cnt;





}