#include <bits/stdc++.h>

using namespace std;

#define ll long long

int main(){
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	string s;cin >> s;
	string a;
	char lst = '#';
	for (auto x : s){
		if (x != lst) {
			a.push_back(x);
			lst = x;
		}
	}

	if (a.size() <= 3){
		cout << a;
	}else{
		int m = a.size();
		if (m & 1) {
			cout << a[0] << a[1] << a[2];
		}else{
			cout << a[0] << a[1];
		}
	}


	return 0;
}