#define _CRT_SECURE_NO_WARNINGS

#include <iostream>
#include <string>
#include <vector>
#include <map>
#include <queue>
#include <algorithm>
#include <cmath>
#include <set>
#include <cstdio>
#include <bitset>
#include <list>
#include <iterator>
#include <time.h>
#include <deque>

#pragma GCC optimize("Ofast")
//#pragma GCC optimize("no-stack-protector")
#pragma GCC optimize("unroll-loops")
//#pragma GCC target("sse,sse2,sse3,ssse3,popcnt,abm,mmx,tune=native")
//#pragma GCC optimize("fast-math")

using namespace std;

typedef long long ll;
typedef long double ld;

#define int long long

const int inf = 1e9 + 7;
const ll INF = 4 * (ll)1e18 + 7;
const ld eps = 1e-9;
const ll mod = 1e9 + 7;

int f(int x)
{
    return 3 * (x * x - 16) * (x * x - 16) + 5;
}
signed main()
{

#ifdef LOCAL
    freopen("output.txt", "w", stdout);
    freopen("input.txt", "r", stdin);
#endif

    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    string word;
    cin >> word;
    string symbols;

    char last = '#';
    for (char ch : word)
    {
        if (ch != last)
            symbols += ch;
        else
            symbols.pop_back();
        last = ch;
    }

    cout << symbols << endl;


    //system("pause");

    return 0;
}