#include <iostream>

using namespace std;

int main()
{
    int n,m; cin >> n >> m; char c[n][m]; bool First = true ,Second = false;

    for(int i = 0 ; i < n ; i++){
        for(int j = 0 ; j < m ; j++){
                if(i%2 != 0 && First ){
                        c[i][m-1] = '#';
                }
                else if(i%2 != 0 && Second){
                    c[i][0] = '#';
                }
                else c[i][j] = '#';
        }
        if(i%2 != 0 && First ){
            First = false ; Second = true;
        }
        else if(i%2 != 0 && Second){
            First = true ; Second = false;
        }
    }
    for(int i = 0 ; i < n ; i++){
        for(int j = 0 ; j < m ; j++){

            if(c[i][j]=='#') cout <<'#';
            else cout<<'.';
        }
        cout << endl;
    }
    return 0;
}