#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i, s, e) for (int i = (int)(s); i < (int)(e); ++i)
#define all(a) (a).begin(),(a).end()

int main() {
    cin.tie(nullptr);
    ios_base::sync_with_stdio(false);
    
    int H, W;
    cin >> H >> W;
    rep(i, 0, H) {
        rep(j, 0, W) cout << ((i/2 + j) % 2 == 0 ? 'X' : 'O');
        cout << '\n';
    }
}