#include <bits/stdc++.h>
#if __has_include (<atcoder/all>)
#include <atcoder/all>
using namespace atcoder;
#endif
#define rep(i, n) for (int i = 0; i < (n); ++i)

using namespace std;

bool isPalindrome(string s) {
    return equal(s.begin(), s.end(), s.rbegin());
}

int main() {
    string a;
    cin >> a;
    
    int n = a.size();
    for (int i = n; i <= n*2; ++i) {
        string s{a};
        for (int j = i-n-1; j >= 0; --j) s += a[j];
        if (isPalindrome(s)) {
            cout << s << '\n';
            return 0;
        }
    }
    
    return 0;
}