*This is my first Kata in the Ciphers series. This series is meant to test our coding knowledge.*
## Ciphers #1 - The 01 Cipher
This cipher doesn't exist, I just created it by myself. It can't actually be used, as there isn't a way to decode it. It's a hash. Multiple sentences may also have the same result.
## How this cipher works
It looks at the letter, and sees it's index in the alphabet, the alphabet being `a-z`, if you didn't know. If it is odd, it is replaced with `1`, if it's even, its replaced with `0`. Note that the index should start from 0. Also, if the character isn't a letter, it remains the same.
## Example
This is because `H`'s index is `7`, which is odd, so it is replaced by `1`, and so on.
Have fun (en)coding!
def encode(s):
    res = ''
    for i in range(len(s)):
        if s[i].isupper():
            if (ord(s[i]) - 65) % 2 == 0:
                res += '0'
            elif (ord(s[i]) - 65) % 2 == 1:
                res += '1'
        elif s[i].islower():
            if (ord(s[i]) - 97) % 2 == 0:
                res += '0'
            elif (ord(s[i]) - 97) % 2 == 1:
                res += '1'
        else:
            res += s[i]
    return res
def encode(s):
    res = ''
    for i in range(len(s)):
        if s[i].isupper():
            if (ord(s[i]) - 65) % 2 == 0:
                res += '0'
            elif (ord(s[i]) - 65) % 2 == 1:
                res += '1'
        elif s[i].islower():
            if (ord(s[i]) - 97) % 2 == 0:
                res += '0'
            elif (ord(s[i]) - 97) % 2 == 1:
                res += '1'
        else:
            res += s[i]
    return res