text: from turtle import Screen
  from snake import Snake
  from food import Food
  from scoreboard import Scoreboard
  import time
  
  screen = Screen()
  screen.setup(width=600, height=600)
  screen.bgcolor("black")
  screen.title("My Snake Game")
  screen.tracer(0)
  
  snake = Snake()
  food = Food()
  score = Scoreboard()
  
  screen.listen()
  screen.onkey(snake.up, "Up")
  screen.onkey(snake.down, "Down")
  screen.onkey(snake.left, "Left")
  screen.onkey(snake.right, "Right")
  
  game_is_on = True
  while game_is_on:
      screen.update()
      time.sleep(0.1)
      snake.move()
  
      # Detect collision with food.
      if snake.head.distance(food) < 15:
          food.refresh()
          score.increase_score()
          snake.extend()
      # Detect collision with wall.
      if snake.head.xcor() > 280 or snake.head.xcor() < -290 or snake.head.ycor() > 280 or snake.head.ycor() < -280: 
          score.reset()
          snake.reset()
  
      # Detect collision with tail.
      for segment in snake.segments[1:]:
          if snake.head.distance(segment) < 10:
              score.reset()
              snake.reset()
  
  
  screen.exitonclick()