#include using namespace std; #if __has_include() #include using namespace atcoder; typedef modint998244353 mint; #endif typedef long long ll; typedef pair pii; typedef pair pll; const int INF = 1e9; const long long LINF = 1e18; const int MOD = 998244353; const int MOD1 = 1e9+7; #define rep(i,n) for(int i=0;i<(int)(n);i++) #define all(x) x.begin(), x.end() template bool chmin(T& a, T b){if(a > b){a = b; return true;} return false;} template bool chmax(T& a, T b){if(a < b){a = b; return true;} return false;} void yorn(bool ans){cout << (ans?"Yes":"No") << endl; return;} bool isPalindrome(string str){ int low = 0, high = str.size()-1; while(low < high){ //不一致が発生した場合 if (str.at(low) != str.at(high))return false; low++; high--; } return true; } // しばらくはsize_tをキャストに任せてみようかな int main(){ string a; cin>> a; int n = a.size(); rep(i,n){ if(isPalindrome(a.substr(i,n))){ cout << a; string b = a.substr(0,i); reverse(all(b)); cout << b << endl; return 0; } } }