picoCTF Writeup picoGym Practice Challenges Matryoshka doll (注意<spoiler>)

```
/picoCTF/Matryoshkadoll$ ls
dolls.jpg
/picoCTF/Matryoshkadoll$ foremost dolls.jpg 
Processing: dolls.jpg
|foundat=base_images/2_c.jpgUT
*|
/picoCTF/Matryoshkadoll$ ls
dolls.dat  dolls.jpg  output
/picoCTF/Matryoshkadoll$ cd output/
/picoCTF/Matryoshkadoll/output$ ls
audit.txt  png  zip
/picoCTF/Matryoshkadoll/output$ cd zip/
/picoCTF/Matryoshkadoll/output/zip$ ls
00000532.zip
/picoCTF/Matryoshkadoll/output/zip$ unzip 00000532.zip 
Archive:  00000532.zip
  inflating: base_images/2_c.jpg
/picoCTF/Matryoshkadoll/output/zip$ ls
00000532.zip  base_images
/picoCTF/Matryoshkadoll/output/zip$ cd base_images/
/picoCTF/Matryoshkadoll/output/zip/base_images$ ls
2_c.jpg
/picoCTF/Matryoshkadoll/output/zip/base_images$ foremost 2_c.jpg 
Processing: 2_c.jpg
|foundat=base_images/3_c.jpgUT
*|
/picoCTF/Matryoshkadoll/output/zip/base_images$ cd output/zip/
/picoCTF/Matryoshkadoll/output/zip/base_images/output/zip$ ls
00000366.zip
/picoCTF/Matryoshkadoll/output/zip/base_images/output/zip$ unzip 00000366.zip 
Archive:  00000366.zip
  inflating: base_images/3_c.jpg
/picoCTF/Matryoshkadoll/output/zip/base_images/output/zip$ ls
00000366.zip  base_images
/picoCTF/Matryoshkadoll/output/zip/base_images/output/zip$ cd base_images/
/picoCTF/Matryoshkadoll/output/zip/base_images/output/zip/base_images$ ls
3_c.jpg
/picoCTF/Matryoshkadoll/output/zip/base_images/output/zip/base_images$ foremost 3_c.jpg 
Processing: 3_c.jpg
|foundat=base_images/4_c.jpgUT
*|
/picoCTF/Matryoshkadoll/output/zip/base_images/output/zip/base_images$ cd output/zip/
/picoCTF/Matryoshkadoll/output/zip/base_images/output/zip/base_images/output/zip$ ls
00000241.zip
/picoCTF/Matryoshkadoll/output/zip/base_images/output/zip/base_images/output/zip$ unzip 00000241.zip 
Archive:  00000241.zip
  inflating: base_images/4_c.jpg
/picoCTF/Matryoshkadoll/output/zip/base_images/output/zip/base_images/output/zip$ ls
00000241.zip  base_images
/picoCTF/Matryoshkadoll/output/zip/base_images/output/zip/base_images/output/zip$ cd base_images/
/picoCTF/Matryoshkadoll/output/zip/base_images/output/zip/base_images/output/zip/base_images$ ls
4_c.jpg
/picoCTF/Matryoshkadoll/output/zip/base_images/output/zip/base_images/output/zip/base_images$ foremost 4_c.jpg 
Processing: 4_c.jpg
|foundat=flag.txtUT
*|
/picoCTF/Matryoshkadoll/output/zip/base_images/output/zip/base_images/output/zip/base_images$ cd output/
/picoCTF/Matryoshkadoll/output/zip/base_images/output/zip/base_images/output/zip/base_images/output$ ls
audit.txt  png  zip
/picoCTF/Matryoshkadoll/output/zip/base_images/output/zip/base_images/output/zip/base_images/output$ cd zip/
/picoCTF/Matryoshkadoll/output/zip/base_images/output/zip/base_images/output/zip/base_images/output/zip$ ls
00000155.zip
/picoCTF/Matryoshkadoll/output/zip/base_images/output/zip/base_images/output/zip/base_images/output/zip$ unzip 00000155.zip
Archive:  00000155.zip
  inflating: flag.txt
/picoCTF/Matryoshkadoll/output/zip/base_images/output/zip/base_images/output/zip/base_images/output/zip$ ls
00000155.zip  flag.txt
/picoCTF/Matryoshkadoll/output/zip/base_images/output/zip/base_images/output/zip/base_images/output/zip$ cat flag.txt 
picoCTF{e3f378fe6c1ea7f6bc5ac2c3d6801c1f}
/picoCTF/Matryoshkadoll/output/zip/base_images/output/zip/base_images/output/zip/base_images/output/zip$ 
```

picoCTF{e3f378fe6c1ea7f6bc5ac2c3d6801c1f}