def is_next_south_cell_empty(i, j, field):
    """
    check if next below cell is empty
    :param i:
    :param j:
    :param field:
    :return: True if next below cell is empty, False otherwise
    """
    if i == len(field) - 1:
        if field[0][j] == '.':
            return True
        return False
    if field[i + 1][j] == '.':
        return True
    return False