Solve the programming task below in a Python markdown code block.
The Story:
Aliens from Kepler 27b have immigrated to Earth! They have learned English and go to our stores, eat our food, dress like us, ride Ubers, use Google, etc. However, they speak English a little differently. Can you write a program that converts our English to their Alien English?

Task:

Write a function converting their speech to ours. They tend to speak the letter `a` like `o` and `o` like a `u`.
```python
>>> convert('hello')
'hellu'
>>> convert('codewars')
'cudewors'
```
Also feel free to reuse/extend the following starter code:
```python
def convert(st):
```