Which 3 mens tennis players have the most grand slam singles championships?
Novak Djokovic, Rafael Nadal, and Roger Federer have the most grand slam singles championships.
### Instruction: Which 3 mens tennis players have the most grand slam singles championships?
### Context: 
### Answer: Novak Djokovic, Rafael Nadal, and Roger Federer have the most grand slam singles championships.</s>