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: Walter White:  Let 's break it down . Hydrogen . What does that give us ?
Gretchen Schwartz: We 're looking at 63 % .
Walter White: Sixty - three , that is a big bite . My next step 's got ta be oxygen .
Gretchen Schwartz: Oxygen , 26 % .
Walter White: Twenty - six . There you have your water .
Gretchen Schwartz: Carbon , 9 % .
Walter White: Carbon , _ 9 _ .
Gretchen Schwartz: For a total of 98 % .
Walter White: Right .
Gretchen Schwartz: Nitrogen , 1.25 % .
Walter White: One - point - two - five .
Gretchen Schwartz: That brings you to 99 and a quarter . Which only leaves you with the trace elements down where the magic happens .
Walter White: Oh , wait a minute . What about calcium ? Calcium 's not a trace . Got a whole skeleton to account for .
Gretchen Schwartz: You would think , right ? Calcium 's only 0.25 % .
Walter White: What ? That low ? Seriously ? Damn , I never would've thought that . Okay , so where does iron fit in .
Gretchen Schwartz: Iron . 4E-05 %
Walter White: What ? You ca n't have hemoglobin without iron .
Gretchen Schwartz: Apparently , it do n't take take much . No doubt . Go figure .
Walter White: Sodium .
Gretchen Schwartz: Sodium , 0.04 % . Phosphorus , 0.19 % .
Walter White: Point - one - nine . There we go . So the whole thing adds up to ... 99.888042 % . We are 0.111958 % . Shy .
Gretchen Schwartz: Supposedly that 's everything .
Walter White: Yeah ? I do n't know , it just ... it seems like something 's missing , does n't it ? There 's got to be more to a human being than that .
Gretchen Schwartz: What about the soul ?
Walter White: The soul ? There 's nothing but chemistry here .

percent