#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<vector>
#include<queue>
#include<cstring>
#include<set>
#include<iomanip>
using namespace std;
string s;
int K,N;
typedef long long LL;
const int coeff[3]={2,3,5};
int main()
{
		freopen("humble.in","r",stdin);
	freopen("humble.out","w",stdout);
  scanf("%d%d",&K,&N);
  for(int i=0;i<K;i++)
  cin>>s;
  priority_queue<LL,vector<LL>,greater<LL> >pq;
  set<LL>s;
  pq.push(1);
  s.insert(1);
  for(int i=1;;i++){
  	LL x=pq.top();pq.pop();
  	if(i==N){
  		cout<<x<<".\n";
	  }
	  for(int j=0;j<3;j++){
	  	LL x2=x*coeff[j];
	  	if(!s.count(x2)){
	  		s.insert(x2);pq.push(x2);
		  }
	  }
  }
  return 0;
}