Given the task definition and input, reply with output. In this task, you will use your knowledge about language (and common sense) to determine what element the marked number refers to. The numbers are marked with two underlines around them, like: _ number _. Your answer should be chosen from the given text, and should not contain other words.

Ronnie Burns: It seems that everything happens in this house . Last time I brought a girl home , Mr. Von Zell showed up with an Indian in full war paint . And another time , mother locked my professor in the closet !
George Burns: Ronnie , if those things did n't happen in this house ... we would n't have _ one _ .
house