NameError

[Cai Gengyang]

>>> pygame.draw.rect(screen, BROWN, [60, 400, 30, 45])
Traceback (most recent call last):
File "<pyshell#3>", line 1, in <module>
pygame.draw.rect(screen, BROWN, [60, 400, 30, 45])
NameError: name 'pygame' is not defined

How to solve this error ?