#include <bits/stdc++.h>

using namespace std;

#define ll long long
#define pii pair <int, int>
#define pb push_back
#define f first
#define s second
#define mp make_pair
#define sz(x) (int)x.size()
#define forit(it, v) for(__typeof(v.begin()) it = v.begin(); it != v.end(); ++it)
#define sqr(x) (x) * 1ll * (x)
#define all(x) x.begin(), x.end()

const int inf = 1e9;
const int mod = 1e9 + 7;
const double eps = 1e-6;


string s;
int p[10100];

int main(){
	ios_base::sync_with_stdio(0), cin.tie(0);

	cin>>s;

	string rs = "";

	int n = sz(s);

	for(int i=0; i<n; i++)
		rs[n-1-i] = s[i];


	p[0] = 0;
	int k = 0;

	for(int i = 1; i<n; i++){
		while(k>0 && rs[k] != rs[i])
			k = p[k-1];
		if(rs[i] == rs[k]) k++;
		p[i] = k;

	}

	k = 0;

	for(int i = 0; i<n; i++){
		while(k>0 && s[i] != s[k]){
			k = p[k-1];        		}
		if(s[i] == s[k])
			k++;
	   	if(k == n)
	   		k = p[k-1];
	}

	cout<<s;

	for(int i=k+1; i<n; i++)
		cout<<rs[i];


	return 0;


}