#include #define rep(i, n) for (int i = 0; i < (int)(n); i++) #define rrep(i, n) for (int i = (int)(n - 1); i >= 0; i--) #define all(x) (x).begin(), (x).end() #define sz(x) int(x.size()) using namespace std; using ll = long long; const int INF = 1e9; const ll LINF = 1e18; template void get_unique(vector& x) { x.erase(unique(x.begin(), x.end()), x.end()); } template bool chmax(T& a, const T& b) { if (a < b) { a = b; return 1; } return 0; } template bool chmin(T& a, const T& b) { if (b < a) { a = b; return 1; } return 0; } template vector make_vec(size_t a) { return vector(a); } template auto make_vec(size_t a, Ts... ts) { return vector(ts...))>(a, make_vec(ts...)); } template istream& operator>>(istream& is, vector& v) { for (int i = 0; i < int(v.size()); i++) { is >> v[i]; } return is; } template ostream& operator<<(ostream& os, const vector& v) { for (int i = 0; i < int(v.size()); i++) { os << v[i]; if (i < sz(v) - 1) os << ' '; } return os; } int main() { string s; cin >> s; int n = sz(s); string ans(1010, 'z'); rep(i, n) { /* s[0..i]+s[i..0] */ { string l = s.substr(0, i + 1); string r = l; reverse(all(r)); string t = l + r; if (sz(t) >= n && t.substr(0, n) == s) { if (sz(t) < sz(ans)) { ans = t; } } } /* s[0..i]+s[i]+s[i..0] */ { string l = s.substr(0, i); string r = l; reverse(all(r)); string t = l + s[i] + r; if (sz(t) >= n && t.substr(0, n) == s) { if (sz(t) < sz(ans)) { ans = t; } } } } cout << ans << '\n'; }