#include<bits/stdc++.h>
using namespace std;
using ll = long long;
using vi = vector<int>;
using vs = vector<string>;
using vvi = vector<vi>;
using vll = vector<ll>;
using vvll = vector<vll>;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
#define rep(i,j,n) for(ll i=j;i<n;i++)
#define rp(i,n) rep(i,0,n)
#define all(v) v.begin(), v.end()
#define pb push_back
#define yes {cout<<"Yes"; return 0;}
#define no {cout<<"No"; return 0;}
#define yn(jg){if(jg) yes; no;}
#define Noo {cout<<-1; return 0;}
#define NL {cout<<endl;}
ll mod0 = 998244353;
ll lmax = 9e18;
ll inf = 2e9;//2147483647
double pi = 3.14159265358979;
//cout<<setprecision(15)<<fixed<<
#define aout(a) {for(auto I:a) cout<<I<<" ";cout<<endl;}
#define bout(a) {for(auto J:a) aout(J);cout<<endl;}
bool kaibun(string s) {
	rp(i, s.size()) if (s[i] != s[s.size() - 1 - i]) return 0;
	return 1;
}
int main() {
	string s,ans; cin >> s;
	rp(i, s.size()) {
		string k;
	//	cout << s.substr(s.size() - 1 - i);
		if(kaibun(s.substr(s.size()-1-i)))  k=s.substr(0,s.size()-i-1);
	//	cout << k << endl;
		reverse(all(k));
		if(kaibun(s) || k!="")ans = s + k;
	}
	cout << ans << endl;
}