use std::io;
fn main() {
    let v = input_nums();
    let n = v[0];
    let v = input_nums();
    let m = v[0];

    let mut target = n;

    for _i in 0..m {
        let v = input_nums();
        if v[0] == target {
            target = v[1];
        } else if v[1] == target {
            target = v[0];
        }
    }
    println!("{}", target);
}

fn input_nums() -> Vec<u64> {
    let mut s = String::new();
    io::stdin().read_line(&mut s).unwrap();
    let mut v = Vec::new();
    for n in s.split_whitespace() {
        v.push(n.parse().unwrap());
    }
    v
}