#include <bits/stdc++.h>
#pragma GCC optimize(2)
#include <iostream>
#include <algorithm>
#include <cstring>
#include <cmath>
#include <queue>
#include <vector>
#include <map>
#include <set>
#include <stack>
#include <unordered_set>
#include <unordered_map>
#define x first
#define y second
#define endl '\n'
using namespace std;
typedef pair<int, int> PII;
typedef pair<double, int> PDI;
typedef pair<PII, int> PIII;
typedef pair<PII, char> PIIC;
typedef long long LL;
int dx[] = {1, 0, 0, -1, -1, -1, 1, 1}, dy[] = {0, -1, 1, 0, -1, 1, -1, 1};
int mou[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
const int N = 1e6 + 10, M = 110, mod = 998244353, INF = 0x3f3f3f3f;
const double eps = 1e-8;
int n, m, t;

void solve()
{
    string s,t;
    cin>>s;n=(int)s.size();
    for(int i=0;i<n;i++)
    {
        t+=s[i];
        while(i+1<n&&s[i]==s[i+1]) ++i;
    }
    if(t.size()>3)
    {
        if(t.size()%2) cout<<t.substr(0,3);
        else cout<<t.substr(0,2);
    }
    else cout<<t;
}

int main()
{
    // ios::sync_with_stdio(false), cin.tie(0), cout.tie(0),cout.precision(10);
    // cin >> t;
    t=1;
    while (t--) solve();
    return 0;
}