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.

Eric Delko: Got a category two hurricane , and we get sent out to a traffic incident ? What 's up with Dispatch ?
Tim Speedle: Well , they 're slammed with thousands of calls , so we take 'em _ one _ at a time till order 's been restored .
Eric Delko: I 'd hate to see what a category four looks like .
Tim Speedle: So would Dispatch .
calls