#include <cstdio>

const int NP = 25;
const int P[NP] = {2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97};

int n,m;
int e[NP], re[NP];

void add ( int x, int e[] ) {
	for (int i = 0; i < NP; ++i)
		for (; x % P[i] == 0; x /= P[i])
			++e[i];
}

int build ( int e[] ) {
	int x = 1;
	for (int i = 0; i < NP; ++i)
		for (int j = 0; j < e[i]; ++j)
			x *= P[i];
	return x;
}

int main() {
	freopen("factoriale.in","rt",stdin);
	freopen("factoriale.out","wt",stdout);
	scanf("%d %d",&n,&m);
	for (int i = 0; i < n; ++i) {
		int a;
		scanf("%d",&a);
		for (int j = 1; j <= a; ++j) add(j,e);
	}

	for (int i = 0; i < NP; ++i) {
		if (e[i] % m != 0) {
			re[i] = ((e[i]/m)+1)*m - e[i];
		}
	}

	printf("%d\n",build(re));
	return 0;
}