#include <stdio.h>
#include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf32 1000000005
#define Inf64 1000000000000000001LL


int main(){
	
	int h,w;
	cin>>h>>w;
	vector<string> s(h,string(w,'l'));
	rep(i,h){
		rep(j,w){
			int t = (i/2) + j;
			t %= 2;
			if(t)s[i][j] = 'X';
			else s[i][j] = 'O';
		}
	}
	rep(i,h)cout<<s[i]<<endl;
}