Definition: 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.
Input: Dr. Sheldon Hawkes:  Found a piece of jewelry , in pretty good shape .
Dr. Sid Hammerback: Based on age , I 'd say they 're probably the victim 's parents .
Dr. Sheldon Hawkes: Job never gets easier , does it ?
Dr. Sid Hammerback: I can tell you I 've been working here twenty - nine years . That 's _ four _ thousand , eight hundred and forty - six cases and names I will never forget .

cases