import java.util.Scanner;

public class Main {
	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		int h = sc.nextInt();
		int w = sc.nextInt();
		sc.close();

		for (int i = 0; i < h; i++) {
			StringBuilder sb = new StringBuilder();
			for (int j = 0; j < w; j++) {
				if (i % 2 == 0 ^ j % 4 < 2) {
					sb.append('O');
				} else {
					sb.append('X');
				}
			}
			System.out.println(sb.toString());
		}
	}
}