use proconio::input;

fn main() {
	input! {
		w: usize,
		h: usize,
		c: char,
	}

	for i in 0..h {
		for j in 0..w {
			print!("{}", if (i+j)%2 == 0 {
				c
			} else if c == 'W' {
				'B'
			} else {
				'W'
			});
		}
		println!();
	}
}