use std::io::*;
use std::str::FromStr;

fn main() {
    let s: Vec<char> = read_array();
    for _i in 0..s.len() - 1{
        if s[_i] == s[_i + 1]{
            continue;
        }
        print!("{}",s[_i]);
    }
    if s[s.len() - 2] != s[s.len() - 1]{
        print!("{}",s[s.len() - 1]);
    }
    if s[s.len() - 2] == s[s.len() - 1]{
        print!("{}",s[s.len() - 1]);
    }
}

pub fn read<T: FromStr>() -> T {
    let stdin = stdin();
    let stdin = stdin.lock();
    let token: String = stdin
        .bytes()
        .map(|c| c.expect("failed to read char") as char)
        .skip_while(|c| c.is_whitespace())
        .take_while(|c| !c.is_whitespace())
        .collect();
    token.parse().ok().expect("failed to parse token")
}

pub fn read_array() -> Vec<char> {
    let array: String = read();
    let chars: Vec<char> = array.trim().chars().collect::<Vec<char>>();
    chars
}