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

string s, u;
int main() {
	registerValidation();
	s = inf.readString();
	inf.readEof();
	u = s[0];
	for(int i = 1; i < (int)s.size(); i++)
		if(s[i - 1] != s[i])
			u += s[i];
	cout << u << endl;
}