import std.stdio, std.algorithm, std.array, std.conv, std.typecons;

void main() {
	auto tmp = readln.split.to!(uint[]);
	auto H = tmp[0], W = tmp[1];
	
	foreach (h; 0 .. H) {
		if ((h%4).among!(0, 1)) {
			foreach (w; 0 .. W)
				write(w%2 == 0 ? "O" : "X");
		}
		else {
			foreach (w; 0 .. W)
				write(w%2 != 0 ? "O" : "X");
		}
		writeln;
	}
}