#include <iostream>
#include <string>
#include <vector>
#include <stdio.h>
using namespace std;

auto PalindromFilter ( vector<string> words, int minLength )
{
    vector<string> otv;
    string w ;
    for (int i=0;i <= words.size();i++ )
    {
        w = words[i];
       int len = w.length();
        if (len >= minLength)
        {
        for(int i = 0; i < len/2; ++i)
            {
            if(w[i] != w[len-1])
            {
                exit;
            } else otv.push_back(w);
        }

        }

    }
    return otv;
    }
  int main() {
      int k=0;
      vector<string> z;
      string x;
      getline(cin,x);
      cin >> k;
      //for (){
      //z.push_back(x);}
      PalindromFilter (z,k);
  return 0;
 }