/* ex_2_3.c++ */
#include <iostream>
#include <string>
using namespace std;

void my_aff_car(const string s) {
	for (int i=0 ;  i<s.length() ; i+=2) {
		cout << s[i]; 
	}
 	cout << endl;   
}

int main () {
	string s_in;
	getline (cin, s_in);
	my_aff_car(s_in);
	return 0;
}