1. Translate from Braille to get `5a42545a42485a42495a42534253457a6361774253457a797a7561776163 and unhex for ZBTZBHZBIZBSBSEzcawBSEzyzuawac` and unhexlify for `ZBTZBHZBIZBSBSEzcawBSEzyzuawac`2. reading the source, "\_" gets replaced with "CTF" before the mixing step, so we can guess the "BSE" in the mixed flag is "CTF" shifted by 253. to get the value for `numShift` we can calculate 25+26 (since CTF is uppercase) = 51, `chr(0x41+51)` gives us "t"4. reverse the `mix` and `puzzled` functions, I opted to do this by editing the provided Python script:```import string
upperFlag = string.ascii_uppercase[:26]lowerFlag = string.ascii_lowercase[:26]MIN_LETTER = ord("a")MIN_CAPLETTER = ord("A")
def reverse_mix(oneLetter, num):    if oneLetter.isupper():        index = upperFlag.index(oneLetter)        shift_index = ord(num)-MIN_CAPLETTER        return chr(MIN_CAPLETTER + (index - shift_index)%len(upperFlag))    else:        index = lowerFlag.index(oneLetter)        shift_index = ord(num)-MIN_LETTER        return chr(MIN_LETTER + (index - shift_index)%len(upperFlag))
def reverse_puzzled(puzzle):    original = ""    pos = 0    while pos < len(puzzle):        if puzzle[pos:pos+3] == "CTF":            original += "_"            pos += 3        else:            if puzzle[pos].isupper():                index = upperFlag.index(puzzle[pos])                index2 = upperFlag.index(puzzle[pos+1])                index3 = upperFlag.index(puzzle[pos+2])                binary = "{0:05b}{1:05b}{2:05b}".format(index, index2, index3)                original += chr(int(binary, 2))                pos += 3            else:                index = lowerFlag.index(puzzle[pos])                index2 = lowerFlag.index(puzzle[pos+1])                hex_val = "{0:01x}{1:01x}".format(index, index2)                original += chr(int(hex_val, 16))                pos += 2    return original
mixed="ZBTZBHZBIZBSBSEzcawBSEzyzuawac"numShift="t"unmixed=""for count, alpha in enumerate(mixed):    unmixed += reverse_mix(alpha, numShift)print(reverse_puzzled(unmixed))```
This prints `THIS_is_easy` and the flag is TUCTF{THIS_is_easy}