use std::collections::HashSet;

use proconio::input;

fn main() {
    input! {
    s: String,
    t: String,
    }

    let mut st: HashSet<String> = [
        "beachball".to_string(),
        "watermelon".to_string(),
        "shrinebell".to_string(),
    ]
    .into_iter()
    .collect();
    st.remove(&s);
    st.remove(&t);
    println!("{}", st.iter().next().unwrap());
}