import pygame

pygame.init()
  
screen = pygame.display.set_mode([600, 400])
  
radius = 10
running = True

while running:
    for event in pygame.event.get():
  
        if event.type == pygame.MOUSEBUTTONDOWN:
            radius = radius + 5
        if event.type == pygame.QUIT:
            running = False

    screen.fill((255,255,255))

    pygame.draw.circle(screen, (0, 0, 0), (300, 200), radius)
  

    pygame.display.update()

pygame.quit()