**Step 1:** Create a function called `encode()` to replace all the lowercase vowels in a given string with numbers according to the following pattern:
```
a -> 1
e -> 2
i -> 3
o -> 4
u -> 5
```
For example, `encode("hello")` would return `"h2ll4"`. There is no need to worry about uppercase vowels in this kata.
**Step 2:** Now create a function called `decode()` to turn the numbers back into vowels according to the same pattern shown above.
For example, `decode("h3 th2r2")` would return `"hi there"`.
For the sake of simplicity, you can assume that any numbers passed into the function will correspond to vowels.
CYPHER = tuple(zip('aeiou', '12345'))

def munge(st, mapping):
    return ''.join([mapping.get(c, c) for c in st])

def encode(st):
    return munge(st, {a: b for a, b in CYPHER})
    
def decode(st):
    return munge(st, {b: a for a, b in CYPHER})

CYPHER = tuple(zip('aeiou', '12345'))

def munge(st, mapping):
    return ''.join([mapping.get(c, c) for c in st])

def encode(st):
    return munge(st, {a: b for a, b in CYPHER})
    
def decode(st):
    return munge(st, {b: a for a, b in CYPHER})
