#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 5; 

int n, m; 
char a[N], b[N]; 

int main(void) {
    ios::sync_with_stdio(0); 
    cin >> a + 1; n = strlen(a + 1); 
    for (int i = 1; i <= n; ++i)
        if (m && b[m] == a[i]) continue; 
        else b[++m] = a[i]; 
    vector<int> del(m + 5); 
    for (int i = 3; i <= m; i += 2)
        if (i + 1 <= m && b[i] == b[i - 2] && b[i + 1] == b[i - 1])
            del[i] = del[i + 1] = 1; 
    for (int i = 1; i <= m; ++i)
        if (!del[i]) cout << b[i]; 
    cout << "\n"; 
    return 0;
}