#include <bits/stdc++.h>
using namespace std;
const int inf = (int)1e9;
const long long INF = (long long)1e18;
const double eps = 1e-9;
const double pi = acos(-1.0);
const int N = 100100;
string second, ans;
int a[30];
int main() {
  cin >> second;
  int i = 0, j = (int)second.size() - 1;
  while (second[i] == second[j] && i <= j) {
    i++, j--;
  }
  if (i > j) {
    return cout << second, 0;
  } else {
    cout << second;
    reverse(second.begin(), second.end());
    cout << second;
  }
  return 0;
}
