import pygame
from pygame.locals import *
import sys 

BLACK = (0,0,0)
RED = (255,0,0)
GREEN = (0,255,0)
BLUE = (0,0,255)
WHITE = (255,255,255)

screen = pygame.display.set_mode((600, 600))
clock = pygame.time.Clock()

while True :
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            sys.exit()

    pygame.display.flip()
    clock.tick(60)