use std::io;

fn main() {
    let mut str = String::new();
    io::stdin().read_line(&mut str).ok().expect("hoge");
    let mut v : Vec<i32> = (0 .. 11).collect();
    for c in str.split_whitespace() {
        let n : i32 = c.parse().ok().expect("hoge");
        for i in 1 .. 11 {
            if n == v[i] {
                v[i] = -1;
            }
        }
    }
    for i in 1 .. 11 {
        if v[i] > 0 {
            println!("{}", i);
        }
    }
}