In this task, you are given a multiple-choice question about healthcare. Answer the question based on your information and classify your answers into '1', '2', '3', and '4'.

Input: Consider Input: Question: In the determination of water hardness due to the presence of Ca2 + and Mg2 + ions, the titrant reagent is used: 
 Options:  <1> Methyl orange. <2> A standard solution of potassium chloride. <3> Black Eriochrome T. <4> A standard solution of ethylenediaminetetraacetic acid (EDTA). <5> A solution of AEDT previously standardized against a solution of potassium phthalate.

Output: 4


Input: Consider Input: Question: The antitussive dextromethorphan is an enantiomer of the O-methylated derivative of levorphanol that belongs to the structural family of: 
 Options:  <1> 6,7-Benzomorpanos. <2> Morfinanos. <3> 4-Phenylpiperidines. <4> Phenylpropalamine. <5> Oripavinas.

Output: 2


Input: Consider Input: Question: The tissue is avascular: 
 Options:  <1> Cartilaginous. <2> Adipose. <3> Osseous. <4> Muscular. <5> Nervous.


Output: 1