use std::io::Read;

fn main() {
    let mut s: String = String::new();
    std::io::stdin().read_to_string(&mut s).ok();
    let mut itr = s.trim().split_whitespace();
    let n: usize = itr.next().unwrap().parse().unwrap();

    let mut ans = std::collections::HashMap::new();
    let mut check = std::collections::HashMap::new();
    let mut name = Vec::new();
    for _ in 0..n {
        let from = itr.next().unwrap();
        let to = itr.next().unwrap();
        let num = ans.entry(from).or_insert(0);
        check.entry(from).or_insert(false);
        check.entry(to).or_insert(false);
        name.push(to);
        *num += 1;
        ans.entry(to).or_insert(0);
    }
    for &i in name.iter() {
        if !check[i] && ans[i] == 0 {
            println!("{}", i);
            check.insert(i, true);
        }
    }
}