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: What amino acids can be bound to a sugar by an O-glycosidic bond? 
 Options:  <1> Ser and Thr. <2> Cys and Ser. <3> Asn and Thr. <4> Lys and His. <5> Val and Leu.

Output: 1


Input: Consider Input: Question: Reactions in which there are no intermediates are described as: 
 Options:  <1> Concerted. <2> Polar <3> Radicals <4> Homolitic <5> Heterolithic

Output: 1


Input: Consider Input: Question: The main method for the preparation of βceto esters is the reaction known as: 
 Options:  <1> Malonic synthesis <2> Acetoacetic synthesis. <3> Condensing of Claisen. <4> Perkin reaction. <5> Hofmann reaction.


Output: 3