#include <iostream>
#include <fstream>
#include <cstring>
using namespace std;
ifstream fin("palindrom.in");
ofstream fout("palindrom.out");
char sir[200005];
long long n, i, j, ok=-1, a=0, b=0, mij, st, dr, MOD=1000000007, p=1;
int main()
{
    fin >> sir;
    n=strlen(sir);
    for(i=n-1; i>=0; i--)
    {
        a=(a*100+(sir[i]-'a'+1))%MOD;
        b=(b+(sir[i]-'a'+1)*p)%MOD;
        p=(p*100)%MOD;
        if(a==b)   ok=i;
    }
    fout << sir;
    for(i=ok-1; i>=0; i--)
        fout << sir[i];
    return 0;
}