#include <bits/stdc++.h>
using namespace std;
#define int long long

int H,W;

signed main(){
  cin>>H>>W;
  vector<vector<char>> A(H,vector<char>(W));
  for(int i = 0; i < H; i++){
    for(int j = 0; j < W; j++){
    	if((i%4 <= 1 && j%2 == 0) || (2 <= i%4 && j%2 == 1)){
    		A[i][j] = 'O';
    	}
    	else{
    		A[i][j] = 'X';
    	}
    }
  }
  for(int i = 0; i < H; i++){
  	for(int j = 0; j < W; j++){
  		cout << A[i][j];
  	}
  	cout << "\n";
  }
}