#include <bits/stdc++.h>

using namespace std;


int main(){
    ios::sync_with_stdio(0);
    cin.tie(0);

    int n, a, b;
    cin >> n >> a >> b;

    bool color = true;

    for(int vertical_tiles = 0; vertical_tiles < n; ++vertical_tiles){
        for(int vertical_length = 0; vertical_length < a; ++vertical_length){
            for(int horizontal_tiles = 0; horizontal_tiles < n; ++horizontal_tiles){
                for(int horizontal_length = 0; horizontal_length < b; ++horizontal_length){
                    cout << (color ? "." : "#");
                }
                color = !color;
            } 
            cout << '\n';
            if(n % 2 != 0){
                color = !color;
            }
        }
        color = !color;
    }

    cout << flush;

    return 0;
}