#include <iostream>
#include <fstream>
#include <cstring>

using namespace std;

ifstream in("palindrom.in");
ofstream out("palindrom.out");

const int lMax = 200005;
const int MOD = 2999999;
const int base = 97;

char s[lMax];
int n;
int hashSt[lMax];
int hashDr[lMax];
int basePow[lMax];

void citire()
{
    in >> (s + 1);
    n = strlen(s + 1) + 1;
}

int GetHashSt(int st, int dr)
{
    long long ret = 1LL * hashSt[dr] - ((1LL * hashSt[st - 1] * basePow[dr - st + 1]) % MOD);
    while(ret < 0)
        ret += MOD;
    ret %= MOD;
    return ret;
}
int GetHashDr(int st, int dr)
{
    long long ret = 1LL * hashDr[st] - ((1LL * hashDr[dr + 1] * basePow[dr - st + 1]) % MOD);
    while(ret < 0)
        ret += MOD;
    ret %= MOD;
    return ret;
}

inline bool palindrom(int st, int dr)
{
    return (GetHashSt(st, dr) == GetHashDr(st, dr));
}

void Code()
{
    for(int i = 1; i < n; ++i)
        hashSt[i] = (hashSt[i-1] * base + s[i]) % MOD;
    for(int i = n - 1; i >= 1; --i)
        hashDr[i] = (hashDr[i + 1] * base + s[i]) % MOD;
}

void SetBasePow()
{
    basePow[0] = 1;
    for(int i = 1; i <= n; ++i)
        basePow[i] = (basePow[i - 1] * base) % MOD;
}

void rezolvare()
{
    Code();
    SetBasePow();
    int rasp = n - 1;
    for(int i = 1; i < n - 1; ++i)
    {
        if(palindrom(i, n - 1))
        {
            rasp = i;
            break;
        }
    }
    out << s + 1;
    for(int i = rasp - 1; i >= 1; --i)
        out << s[i];
}

int main()
{
    citire();
    rezolvare();

    return 0;
}