#include <bits/stdc++.h>
using namespace std;
int main(){
  string A;
  cin >> A;
  int N = A.size();
  for (int i = N; i <= N * 2 - 1; i++){
    vector<char> S(i, '.');
    bool ok = true;
    for (int j = 0; j < N; j++){
      S[j] = A[j];
    }
    for (int j = 0; j < N; j++){
      if (S[i - 1 - j] != '.' && S[i - 1 - j] != A[j]){
        ok = false;
      }
      S[i - 1 - j] = A[j];
    }
    if (ok){
      for (int j = 0; j < i; j++){
        cout << S[j];
      }
      cout << endl;
      break;
    }
  }
}