#include <stdio.h>
FILE*f=fopen("factoriale.in","r");
FILE*g=fopen("factoriale.out","w");
int X,n,z,i,j,k,x,p[50],v[102];
long long sol;
int main() {
	for(i=2;i<=100;i++)
		if(v[i]==0){
			for(j=2*i;j<=100;j+=i)
				v[j]=1;
			p[++k]=i;
		}
	for(i=1;i<=100;i++)
		v[i]=0;
	fscanf(f,"%d%d",&n,&z);
	for(i=1;i<=n;i++){
		fscanf(f,"%d",&x);
		for(j=2;j<=x;j++){
			k=1;
			X=j;
			while(X!=1){
				while(X%p[k]==0){
					v[p[k]]++;
					X/=p[k];
				}
				k++;
			}
		}
	}
	sol=1;
	for(i=2;i<=100;i++)
		if(v[i]%z!=0)
			for(j=1;j<=(z-v[i]%z);j++)
				sol*=i;
				
		
	fprintf(g,"%d",sol);	
	fclose(g);
	fclose(f);
	return 0;
}