fn read_vec<T: std::str::FromStr>() -> Vec<T> {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    s.trim()
        .split_whitespace()
        .map(|e| e.parse().ok().unwrap())
        .collect()
}

fn main() {
  use std::collections::VecDeque;

  let nm:Vec<usize> = read_vec();
  let ops:Vec<usize> = read_vec();

  let mut sort:VecDeque<usize> = VecDeque::new();
  for i in 0..nm[0] {
    sort.push_back(i+1);
  }

  for i in 0..ops.len() {
    let temp = sort.remove(ops[i]-1).unwrap();
    sort.push_front(temp);
  }

  println!("{}", sort[0]);
}