#include <bits/stdc++.h>
using namespace std;
ifstream fin("ordine.in");
ofstream fout("ordine.out");
int n;
char s[100005];
int main()
{
    int i,j;
    char last;
    fin>>(s+1);
    fout<<(s+1);
    n = strlen(s);
    //sort(s,s+n);
    last = '!';
    /*for(i = 0, j = 1;s[i]; i++)
    {
        if(s[i]=='!') continue;

        if(s[i]!=last)
        {
            fout<<s[i];
            last = s[i];
        }
        else
        {
            while(s[j] && s[j]==s[i]) j++;
            if(s[j]!=s[i])
            {
                fout<<s[j];
                s[j] = '!';
            }
        }
        if(j <=i) j = i+1;
    }*/
    fout.close();
    return 0;
}