********************************************************************************
Step 1
********************************************************************************

------Action------
THOUGHT:
None
ACTION TYPE:
None
ACTION CONTENT:
None

-----Response-----
RESPONSE (User Message):
USER QUERY: Given a list of hex-encoded strings, decode each one from hex to ASCII, reverse it, and then apply a Caesar cipher decode with a shift of 4. Find the length of the shortest decoded message. The list of hex strings is ['636261', '686766', '6365646362', '6867666865'].
Save the final answer in the variable `final_answer`.

Use the code base located at `/root/m3eval/m3eval` to solve this query. Your current directory is `/root/playground`.

If the import path in retrieved code block says `testing/dir_name/file_name.py` and you want to import variable, function or class called `obj` from this file, then import using `from testing.dir_name.file_name import obj`.

The code base path has either been installed via pip or has been already been added to the system path via
```
import sys
sys.path.extend(['/root/m3eval'])
```

********************************************************************************
Step 2
********************************************************************************

------Action------
THOUGHT:
Before writing the code to decode the hex strings, reverse them, and apply a Caesar cipher decode, I need to search the codebase for any existing functions that can perform these operations. I will start by searching for functions related to decoding hex strings to ASCII.
ACTION TYPE:
search
ACTION CONTENT:
(type: FUNCTION) AND (text: hex AND text: ascii)

-----Response-----
RESPONSE (Retrieval Result):
QUERY:
(type: FUNCTION) AND (text: hex AND text: ascii)

CODE BLOCKS:
---
file_path=m3eval/message_decoder.py
lines=[0, 3]
type=FUNCTION
content={
def convert_hex_to_ascii(hex_string: str):
    ascii_string = bytes.fromhex(str(hex_string)).decode('utf-8')
    return ascii_string
}
---
(All code blocks matching the query were returned.)

********************************************************************************
Step 3
********************************************************************************

------Action------
THOUGHT:
We have found a function `convert_hex_to_ascii` that can convert hex strings to ASCII. Next, I will search for a function that can perform a Caesar cipher decode.
ACTION TYPE:
search
ACTION CONTENT:
(type: FUNCTION) AND (text: caesar AND text: decode)

-----Response-----
RESPONSE (Retrieval Result):
QUERY:
(type: FUNCTION) AND (text: caesar AND text: decode)

CODE BLOCKS:
---
file_path=m3eval/message_decoder.py
lines=[9, 17]
type=FUNCTION
content={
def caesar_decode(message: str, shift: int):
    """Caesar cipher decoder."""
    shift = int(shift)
    decoded = ''.join(chr((ord(char) - shift - 65) % 26 + 65)
                      if char.isupper() else chr((ord(char) - shift - 97) % 26 + 97)
                      if char.islower() else char
                      for char in message)
    return decoded
}
---
(All code blocks matching the query were returned.)

********************************************************************************
Step 4
********************************************************************************

------Action------
THOUGHT:
We have found a function `caesar_decode` that can perform a Caesar cipher decode. Now, I will write the code to import these functions, process the list of hex-encoded strings as per the user's instructions, and find the length of the shortest decoded message.
ACTION TYPE:
code
ACTION CONTENT:
from m3eval.message_decoder import convert_hex_to_ascii, caesar_decode

# List of hex-encoded strings
hex_strings = ['636261', '686766', '6365646362', '6867666865']

# Decode each hex string to ASCII, reverse it, and apply a Caesar cipher decode with a shift of 4
decoded_messages = [caesar_decode(convert_hex_to_ascii(s)[::-1], 4) for s in hex_strings]

# Find the length of the shortest decoded message
final_answer = len(min(decoded_messages, key=len))

-----Response-----
RESPONSE (Execution Result):
CODE EXECUTED WITHOUT ERROR, STDOUT WAS EMPTY
RELEVANT VARIABLES (only shown if string rep. has changed after code exec):
{"convert_hex_to_ascii": <function convert_hex_to_ascii at 0x7f89b8bd3ec0>, "caesar_decode": <function caesar_decode at 0x7f89b8b2cd60>, "hex_strings": ['636261', '686766', '6365646362', '6867666865'], "decoded_messages": ['wxy', 'bcd', 'xyzay', 'adbcd'], "final_answer": 3}

********************************************************************************
Step 5
********************************************************************************

------Action------
THOUGHT:
The code has been executed without error, and the variable `final_answer` contains the length of the shortest decoded message, which is 3. The task is completed successfully.
ACTION TYPE:
done
ACTION CONTENT:
True

-----Response-----
None