#include <bits/stdc++.h>
using namespace std;
const int INF = 1e9;
int main() {
  string s;
  cin >> s;
  int n = s.length();
  for (int(i) = 0; (i) < (n); ++(i)) cout << s[i];
  for (int(i) = (n - 1); (i) >= (0); --i) cout << s[i];
  cout << endl;
  return 0;
}
