use std::collections::*;

#[allow(unused)]
struct Scanner {
    stack: VecDeque<String>,
    input: std::io::Stdin,
}

impl Scanner {
    fn new() -> Scanner {
        Scanner {
            stack: VecDeque::<String>::new(),
            input: std::io::stdin(),
        }
    }
    fn take(&mut self) -> Option<String> {
        if let Some(s) = self.stack.pop_front() {
            return Some(s);
        }
        self.enqueue_from_line();
        self.stack.pop_front()
    }
    fn enqueue_from_line(&mut self) {
        let mut t = String::new();
        self.input.read_line(&mut t).ok();
        t.trim()
            .split_ascii_whitespace()
            .for_each(|s| self.stack.push_back(s.to_owned()));
    }
}

macro_rules! scan {
    ($io:expr => $t:ty) => {
        $io.take().unwrap().parse::<$t>().unwrap()
    };
    ($io:expr => $t:tt * $n:expr) => ((0..$n).map(|_| scan!($io => $t)).collect::<Vec<_>>());
    ($io:expr => $($t:tt),*) => (($(scan!($io => $t)),*));
}

fn main() {
    let mut cin = Scanner::new();
    let n = scan!(cin => i32);
    let aa = scan!(cin => String * n);
    let mut map = btree_map::BTreeMap::<String, i32>::new();
    for e in aa {
        let v = map.get(&e).unwrap_or(&0) + 1;
        map.insert(e, v);
    }
    let bb = scan!(cin => String * (n-1));
    for e in bb {
        let v = map.get(&e).unwrap_or(&0) - 1;
        map.insert(e, v);
    }
    for (k, v) in map {
        if v > 0 {
            println!("{}", k);
        }
    }
}