text: // Ivan Carvalho
  // Solution to https://www.urionlinejudge.com.br/judge/problems/view/2176
  #include <iostream>
  #include <string>
  #define endl '\n'
  using namespace std;
  int main(){
         	ios_base::sync_with_stdio(0);
         	cin.tie(0);
         	string entrada;
         	cin >> entrada;
         	int uns = 0;
         	for(int i=0;i<entrada.size();i++) uns += (int)(entrada[i]=='1');
         	cout << entrada;
         	if (uns % 2 == 0) cout << "0" << endl;
         	else cout << "1" << endl;
         	return 0;
  }
  