import pygame
import random

WIDTH = 500
HEIGHT = 500
FPS = 60

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

pygame.init()
screen = pygame.display.set_mode((WIDTH, HEIGHT))
f1 = pygame.font.Font(None, 36)
running = True
screen.fill(BLACK)
counter = 0
for it_1 in range(0,500,100):
 for it_2 in range(0,500,100):
  pygame.draw.rect(screen,WHITE, (it_1,it_2,99,99))
while running:
    
    for event in pygame.event.get():
        
     if event.type == pygame.QUIT:
            running = False
     if event.type == pygame.MOUSEBUTTONDOWN:
        if event.button == 1:
         x, y  = pygame.mouse.get_pos()
         x = x//100 * 100
         y = y//100 * 100
         font = pygame.font.SysFont(None, 24)
         img = font.render(str(counter), True, BLACK)
         screen.blit(img, (x+49, y+49))
         counter = counter + 1

    pygame.display.update()
    
pygame.quit()