#include <iostream>
#include <string>
#include <map>
#include <vector>
#include <set>

using namespace std;

int main()
{
    string word;
    getline(cin, word);
    vector<char> symbols;
    symbols.push_back('5');
    for (int i = 0; i < word.size(); i++)
    {
        if (word[i] != symbols[symbols.size()-1])
        {
            symbols.push_back(word[i]);
        }
        else
        {
            symbols.pop_back();
        }
    }
    for (int i = 1; i < symbols.size(); i++)
    {
        cout << symbols[i];
    }
    return 0;
}