Output the updated list with the element "onions" added to it.
Tomatoes, potatoes, mushrooms
Tomatoes, potatoes, mushrooms, onions
Complete the following task based on the instruction and optional input provided.### Instruction:
Output the updated list with the element "onions" added to it.

### Input:
Tomatoes, potatoes, mushrooms

### Output:
Tomatoes, potatoes, mushrooms, onions