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'.

Example Input: Question: ADH increases the osmolality of the renal interstitial medium because it increases: 
 Options:  <1> The permeability to urea in the collector tube. <2> The water permeability of the ascending loop of Henle. <3> The flow in the straight vessels. <4> The reabsorption of NaCl in the collecting tubule. <5> The renal excretion of water.
Example Output: 1

Example Input: Question: The pentose phosphate pathway produces: 
 Options:  <1> NADH and acetyl-CoA. <2> NADPH and ribose-5-phosphate. <3> NADH and ribose-5-phosphate. <4> Urea. <5> Ribulose-1,5-bisphosphate.
Example Output: 2

Example Input: Question: Topoisomerases: 
 Options:  <1> They modify the degree of DNA supercoiling. <2> They are a type of DNA polymerases. <3> They bind to the single-stranded DNA to prevent the double helix from forming. <4> They exhibit exonuclease activity. <5> They synthesize dNTPs.
Example Output:
1