Xin Tao: Yang Yang, have you bought your socks?
Yang Yang: What for?
X: To hold Christmas gifts! Santa Claus always holds gifts inside socks.
Y: But the gift you want this year is very big. I reckon the sock will not be able to hold it. However, I believe Santa Claus has surely a way out.
X: You want a Christmas gift that big and at least how big?
Y: It's a secret!