def METHOD_NAME(line):
    global min_x, max_x, min_y, max_y, last_z
    current_x = find_axis(line, 'x')
    current_y = find_axis(line, 'y')
    if current_x is not None:
        min_x = min(current_x, min_x)
        max_x = max(current_x, max_x)
    if current_y is not None:
        min_y = min(current_y, min_y)
        max_y = max(current_y, max_y)
    return min_x, max_x, min_y, max_y