#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>

using namespace std;

const int N = 250009;
char s[N];

int main()
{
    scanf("%s", s);
    int len, i, j;
    len = strlen(s);
    for (i = 1, j = 0; i < len; ++i) {
        if (s[i] == s[j]) {
            s[i] = 96;
            s[j] = 96;
            i++;
            while (s[j] == 96)  j--;
            while (j>=0 && i<len && s[i] == s[j]) {
                s[j] = 96;
                s[i] = 96;
                j--;
                i++;
            }
            j = i;
        }
        else
            j = i;
    }
    for (i = 0; i < len; ++i)
        if (s[i] != 96)
            printf("%c", s[i]);
    printf("\n");
    return 0;
}