def Main():
    n, m = map(int, input().split())

    for i in range(1, n+1):
        if i%2 == 1:
            print('#' * m)
        elif (i//2)%2 == 1:
            print('.' * (m-1) + '#')
        else:
            print('#' + '.' * (m-1))

if __name__ == "__main__":
    Main()
