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: The determination of cyanide by the Liebig method is based on the addition of a silver nitrate standard solution: 
 Options:  <1> Until complete precipitation of silver cyanide. <2> Until the precipitation of silver cyanide begins. <3> Until the appearance of a red precipitate of silver chromate. <4> Until the AgCN complex is quantitatively formed. <5> Until the precipitation of silver iodide, yellow.
Example Output: 2

Example Input: Question: The oppressive / tightening pain, of light to moderate intensity, of bilateral localization and that does not worsen with routine physical activity, is what occurs in: 
 Options:  <1> Pelvic pain <2> The burnout. <3> Asthma. <4> Irritable bowel syndrome. <5> Tension headache.
Example Output: 5

Example Input: Question: The nitrogen: 
 Options:  <1> It is a highly reactive gas at room temperature. <2> Nitrogen molecules are constituted by two atoms linked together by a single bond. <3> It has a higher reactivity than other isoelectronic molecules such as CO, CNo or NO +. <4> At a sufficient temperature, it reacts with H2 to give NH3. <5> It barely forms binary compounds with the rest of the elements of the Periodic Table.
Example Output:
4