#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  ;
  {
    string s;
    cin >> s;
    stack<char> s1;
    queue<char> q;
    for (long long i = 0; i < s.size(); i++) {
      s1.push(s[i]);
      q.push(s[i]);
    }
    while (!q.empty()) {
      cout << q.front();
      q.pop();
    }
    while (!s1.empty()) {
      cout << s1.top();
      s1.pop();
    }
    cout << endl;
  }
  return 0;
}
