use std::io::Read;

fn main() {
	let mut s = String::new();
	std::io::stdin().read_to_string(&mut s).ok();
	let s = s.lines().nth(1).unwrap();
	('A'..='Z')
		.map(|c| s.matches(c).count())
		.for_each(|x| print!("{}", x));
	println!()
}