#include <cstdio>  //此代码为网上所复制

 #include <iostream>

 #include <string>

 #include <set>

 #include <algorithm>

 #include <vector>

 using namespace std;

 bool Comp(const string &s1, const string &s2)

 {

     return s1.length() != s2.length() ? s1.length()<s2.length() : s1<s2;

 }

 int main()

 {

     vector<string> v;

     string t, s;

     int n;

     cin >> n;

     getchar();

     while (n--)

     {

         getline(cin, s);

         t = s;

         //反转字符串，用来判断字符是否对称

         reverse(t.begin(), t.end());

         if (t == s)

         {

             v.push_back(s);

         }

     }

     sort(v.begin(), v.end(), Comp);

     for (int i = ; i<v.size(); i++)

     {

         cout << v[i] << endl;

     }

     return ;

 }