一次小試身手，題目有關於 git 指令。
看到問題，題目想要問將每個人新增的東西結合起來會怎麼樣，並且給了很多關於 git 的提示。

hint 1：git branch -a will let you see available branches
hint 2 ：How can file 'diffs' be brought to the main branch? Don't forget to git config!
hint 3：Merge conflicts can be tricky! Try a text editor like nano, emacs, or vim.

首先，我們先看到下載了甚麼東西。發現得到一個壓縮檔，叫做 challenge.zip。

$ ls -l
total 32
-rwxrwxr-x 1 s109056003 s109056003 24640  七  27 21:19 challenge.zip

使用 chmod 給予壓縮檔執行權限，再來解壓縮，會出現一個 drop-in 的檔案。

$ chmod +x challenge.zip 
$ unzip challenge.zip 
Archive:  challenge.zip
   creating: drop-in/
   creating: drop-in/.git/
   creating: drop-in/.git/branches/
  inflating: drop-in/.git/description  
   creating: drop-in/.git/hooks/
  inflating: drop-in/.git/hooks/applypatch-msg.sample  
  inflating: drop-in/.git/hooks/commit-msg.sample  
  inflating: drop-in/.git/hooks/fsmonitor-watchman.sample  
  inflating: drop-in/.git/hooks/post-update.sample  
  inflating: drop-in/.git/hooks/pre-applypatch.sample  
  inflating: drop-in/.git/hooks/pre-commit.sample  
  inflating: drop-in/.git/hooks/pre-merge-commit.sample  
  inflating: drop-in/.git/hooks/pre-push.sample  
  inflating: drop-in/.git/hooks/pre-rebase.sample  
  inflating: drop-in/.git/hooks/pre-receive.sample  
  inflating: drop-in/.git/hooks/prepare-commit-msg.sample  
  inflating: drop-in/.git/hooks/update.sample  
   creating: drop-in/.git/info/
  inflating: drop-in/.git/info/exclude  
   creating: drop-in/.git/refs/
   creating: drop-in/.git/refs/heads/
 extracting: drop-in/.git/refs/heads/main  
   creating: drop-in/.git/refs/heads/feature/
 extracting: drop-in/.git/refs/heads/feature/part-1  
 extracting: drop-in/.git/refs/heads/feature/part-2  
 extracting: drop-in/.git/refs/heads/feature/part-3  
   creating: drop-in/.git/refs/tags/
 extracting: drop-in/.git/HEAD       
  inflating: drop-in/.git/config     
   creating: drop-in/.git/objects/
   creating: drop-in/.git/objects/pack/
   creating: drop-in/.git/objects/info/
   creating: drop-in/.git/objects/77/
 extracting: drop-in/.git/objects/77/d6ceca6fe23b57d88cf16f20003e10d6715690  
   creating: drop-in/.git/objects/b9/
 extracting: drop-in/.git/objects/b9/32e8c048154a46d224cd7691c99dc8cb88164a  
   creating: drop-in/.git/objects/22/
 extracting: drop-in/.git/objects/22/58a0f267d57e8b6025e2a020b77fac7a553c92  
   creating: drop-in/.git/objects/6e/
 extracting: drop-in/.git/objects/6e/17fb3a35364b4f9bb8bef8b5e6a5af2d3e7dfa  
   creating: drop-in/.git/objects/43/
 extracting: drop-in/.git/objects/43/e44dd37ba0c0adc3d78d0b85d699859ec8d75c  
   creating: drop-in/.git/objects/8e/
 extracting: drop-in/.git/objects/8e/ea0627726fc363246015cb4c7e927e70286e87  
   creating: drop-in/.git/objects/7a/
 extracting: drop-in/.git/objects/7a/b4e25c0cd108374b2275fdb1fcdf635e591833  
   creating: drop-in/.git/objects/d1/
 extracting: drop-in/.git/objects/d1/f3407cee4479c075997b497fa290ca636fe258  
   creating: drop-in/.git/objects/05/
 extracting: drop-in/.git/objects/05/db9e274ff691e0f9fb492403b570629eb80aa9  
   creating: drop-in/.git/objects/4f/
 extracting: drop-in/.git/objects/4f/136da027f9a97032d53dd5f667dd6c7852737c  
   creating: drop-in/.git/objects/dd/
 extracting: drop-in/.git/objects/dd/f6fd2129098bf677ac010259a2a642060aea47  
   creating: drop-in/.git/objects/65/
 extracting: drop-in/.git/objects/65/5c7bfebe9c221369ab00ac7374d0d4bd4d62a9  
  inflating: drop-in/.git/index      
 extracting: drop-in/.git/COMMIT_EDITMSG  
   creating: drop-in/.git/logs/
  inflating: drop-in/.git/logs/HEAD  
   creating: drop-in/.git/logs/refs/
   creating: drop-in/.git/logs/refs/heads/
  inflating: drop-in/.git/logs/refs/heads/main  
   creating: drop-in/.git/logs/refs/heads/feature/
  inflating: drop-in/.git/logs/refs/heads/feature/part-1  
  inflating: drop-in/.git/logs/refs/heads/feature/part-2  
  inflating: drop-in/.git/logs/refs/heads/feature/part-3  
  inflating: drop-in/flag.py         

接著使用 ls -R ，這個指令的意思是，將資料夾底下的檔案夾逐一顯示，看到 drop-in 資料夾中有一個 flag.py。

$ ls -R
.:
challenge.zip  drop-in  step.txt

./drop-in:
flag.py

然後，我們使用 cat 檢視 flag.py，但是沒有看到 flag 的資訊。

$ cd drop-in/
$ cat flag.py
print("Printing the flag...")

於是想起 hint，提示有給 git branch -a 使用這個指令，可以知道我們現在在哪個分支。( 其實在解壓縮 challange.zip 時，也能看到有三個分支 )

使用 git branch -a，我們可以看到現在在 main 底下，並且有 3 個分支。

$ git branch -a
  feature/part-1
  feature/part-2
  feature/part-3
* main

於是使用 git checkout ，更改所在的分支，並且逐一將每個分支底下的 flag 結合，就可以得到 flag 了。

當然您也可以使用 merge，但是提示說可能會比較麻煩，因此在這裡我選擇一一將 flag 合併就好了。

$ git checkout feature/part-1; cat flag.py
Already on 'feature/part-1'
print("Printing the flag...")
print("picoCTF{t3@mw0rk_", end='')

$ git checkout feature/part-2; cat flag.py
Switched to branch 'feature/part-2'
print("Printing the flag...")

print("m@k3s_th3_dr3@m_", end='')

$ git checkout feature/part-3; cat flag.py
Switched to branch 'feature/part-3'
print("Printing the flag...")

print("w0rk_6c06cec1}")

總結：
我們學習了使用 git 指令來管理分支並解決合併衝突，並且通過切換分支並合併 flag.py 的內容，我們成功找到了 flag。