#include <bits/stdc++.h>
using namespace std;
#include "testlib.h"

string s, u;
int main() {
	registerValidation();
	s = inf.readString();
	inf.readEof();
	for(auto &c : s) {
		assert('a' <= c and c <= 'z');
	}
	for(int i = 0; i < (int)s.size() - 2; i++) {
		if(s[i] == s[i + 1] and s[i + 1] == s[i + 2])
			assert(false);
	}
	u = s[0];
	for(int i = 1; i < (int)s.size(); i++)
		if(s[i - 1] != s[i])
			u += s[i];
	cout << u << endl;
}