Alan Mak: It wasn't difficult because of Andrew...
Andrew Lau: I'm the "Big Brother" (Da Ge/Dai Go). Andy, Tony, Anthony, Eric, we all worked together when I was young. So, I've known a lot of these famous actors for many years. Andy and Tony looked at the script, and I asked which character each wanted to do. At that moment, they knew which character they wanted. Their choices ended up being suitable. I wasn't sure about the chemistry, and I wanted to change, but it really turned out right.