Who are the most successful US Olympic swimmers?
Michael Phelps, Mark Spitz, Katie Ledecky, Missy Franklin
Below is an instruction that describes a task, paired with an input that provides further context. Write a response that appropriately completes the request.
### Instruction: Who are the most successful US Olympic swimmers?
### Input: 
### Response: Michael Phelps, Mark Spitz, Katie Ledecky, Missy Franklin