#include<stdio.h>
FILE *f=fopen("factoriale.in","r"),
     *g=fopen("factoriale.out","w");
int n,i,j,a[101],p[101],k,c[101],pr,ok,x,y,t;
long long q;
int main()
{ p[0]=2;
  p[1]=3;
  p[2]=5;
  i=7;k=2;
  while(i<100) { ok=1;
		 for(j=1;j<=k&&ok;++j) if(i%p[j]==0) ok=0;
		 if(ok) p[++k]=i;
		 i+=2;
	       }
  pr=k;
  fscanf(f,"%d %d",&n,&k);
  for(i=1;i<=n;++i) { fscanf(f,"%d",&y);
		      for(t=2;t<=y;++t){ x=t;
		      for(j=0;j<=pr&&x>1;++j) while(x%p[j]==0) x/=p[j],++c[j];
		      }
		    }
  q=1;
  for(i=0;i<=pr;++i) { c[i]%=k;   if(c[i]) c[i]=k-c[i];
		       for(j=1;j<=c[i];++j) q*=p[j];
		     }
  fprintf(g,"%lld\n",q);
  fclose(f);
  fclose(g);
  return 0;
}