#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const ll mod = 1e9 + 7;
const int N = 200005;
const int INF = 0x3f3f3f3f;

int main() {
    int n, m;
    cin >> n >> m;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            if ((i + j / 2) % 2 == 1) {
                cout << "O";
            } else {
                cout << "X";
            }
        }
        cout << "\n";
    }
    return 0;
}