# Warmup
*A fun visual cryptogr aphy tool will amaze your kids!*
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题目中给出了两张灰度图`ciphered_message.png`和`secret.png`,先用`PIL`看一下图片中每个像素点的值,发现均为0或255.
```pythonfrom PIL import Imageim = Image.open('ciphered_message.png')print(list(im.getdata()))```
使用`PIL`合并两张图片即可.
```Pythonfrom PIL import Image
im = Image.open('ciphered_message.png')im2 = Image.open('secret.png')assert im.size == im2.sizesize = im2.sizeprint(size)print(im.mode)data = [x for x in im.getdata()]for index,x in enumerate(im2.getdata()):    if x and data[index]:        data[index] = 255    else:        data[index] = 0
im = Image.new('1',size)im.putdata(data)im.save('ans.png')```
![TMUCTF](assets/ans.png)
**flag:**`TMUCTF{W3_h0p3_y0u_3nj0y_7h15_c0mp371710n_4nd_7h4nk_y0u!}`
