diff --git a/snake.py b/snake.py
index 537316e..c06412a 100644
--- a/snake.py
+++ b/snake.py
@@ -1,11 +1,11 @@
 import pygame
 from pygame import locals
-
+import random
 # 初始化pygame，为使用硬件做准备
 pygame.init()
 
 # 创建一个窗口
-screen = pygame.display.set_mode((660, 480))
+screen = pygame.display.set_mode((780, 600))
 FPSCLOCK = pygame.time.Clock()  # pygame时钟，控制游戏速度（帧数）
 
 # 背景
@@ -18,6 +18,7 @@ up = pygame.image.load('up.png')            # 头 朝上
 down = pygame.image.load('down.png')        # 头 朝下
 
 x, y = 240, 120
+ax,ay = 360,300
 position = [(180, 90), (180, 120), (210, 120), (x, y)]
 
 setheading = "right"
@@ -52,7 +53,13 @@ while True:
     else:
         y += 30
     position.append((x, y))
-    position.pop(0)
+    if ax==x and ay==y:
+        a1=random.randint(1,26)
+        a2=random.randint(1,20)
+        ax=a1*30-30
+        ay=a2*30-30
+    else:
+        position.pop(0)
     # 将背景图画上去
     screen.blit(background, (0, 0))
     # 将贪吃蛇的头画上去
@@ -62,7 +69,7 @@ while True:
         screen.blit(body, position[i])
 
     # 将果实画上去
-    screen.blit(food, (360, 300))
+    screen.blit(food, (ax, ay))
     # 刷新画面
     pygame.display.update()
     FPSCLOCK.tick(3)
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