import pygame
import random
pygame.init()

screen = pygame.display.set_mode([500, 500])
RED = (255, 0, 0)
GREEN =(0,255, 0)
BLUE = (0,0,255)
x1 = 0
y1 = 0
speedX = 1
speedY = 1
counter = 0
running = True
while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False

    if x1 > 475:
        speedX = -speedX

    if x1 < 0: speedX = -speedX
    if y1 > 460: 
     speedY = -speedY
    if y1 < 0: speedY = -speedY
    counter+=1
    if counter < 10000:
     pygame.draw.rect(screen,RED, (x1,y1, 5, 5))
    
     pygame.draw.rect(screen,GREEN, (x1+10,y1+10, 5, 5))
    
     pygame.draw.rect(screen,BLUE, (x1+20,y1+20, 5, 5))

    pygame.display.flip()
    x1 = x1 + speedX
    y1 = y1 + speedY
    
pygame.quit()