use std::io::Read;

fn main() {
	let mut s = String::new();
	std::io::stdin().read_to_string(&mut s).ok();
	let s = s.split_whitespace().collect::<Vec<_>>().join("");
	let a = s == "#.#.#.#.#" || s == ".#.#.#.#.";
	println!("{}", if a { "Yes" } else { "No" });
}