#include <iostream>
#include <vector>
#include <cmath>
#include <algorithm>
#include <string>

using namespace std;

string chipher(string s)
{
	string ans;
	int mark = 1;
	for (int i = 1; i < s.size(); ++i)
	{
		if (s[i - 1] != s[i])
		{
			ans.push_back(s[i - 1]);
			if (i == s.size() - 1)
			{
				ans.push_back(s[i]);
			}
		}
		else
		{
			int cnt = 1;
			while (i < s.size() && s[i - 1] == s[i])
			{
				++cnt, ++i;
			}
			if (cnt % 2 != 0)
			{
				ans.push_back(s[i - 1]);
			}
			++mark;
		}
	}
	if (mark != 1)
	{
		chipher(ans);
	}
	else
	{
		string trueans = ans;
		return trueans;
	}
}

int main()
{
	string s;
	cin >> s;

	s = chipher(s);
	for (int i = 0; i < s.size(); ++i)
	{
		cout << s[i];
	}
}