use std::io::Read;

fn main() {
	let mut s = String::new();
	std::io::stdin().read_to_string(&mut s).ok();
	let mut s = s.split_whitespace().flat_map(str::parse::<usize>);
	let n = s.next().unwrap();
	let mut v: Vec<_> = (1..=n).rev().collect();
	s.skip(1).for_each(|a| {
		let i = v.remove(n - a);
		v.push(i)
	});
	println!("{}", v.last().unwrap());
}