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: Except in patients whose chronic renal failure is due to diabetic nephropathy or tubulointerstitial nephropathy, the arterial blood gas pattern that you would expect to find in a patient with chronic renal failure would be: 
 Options:  <1> pH 7.30, HCO3 18 mEq / L, Cl 116 mg / dL, because metabolic acidosis with normal anion gap is characteristic. <2> pH 7.46, HCO3 18 mEq / L, Cl 116 mg / dL, because hyperchloremic metabolic alkalosis is characteristic. <3> pH 7.456, HCO3 18 mEq / L, Cl 100 mg / dL, because metabolic acidosis with increased anion gap is characteristic. <4> pH 7.46, HCO3 30 mEq / L, Cl 90 mg / dL, because metabolic alkalosis with normal anion gap is characteristic. <5> pH 7.45, HCO3 23 mEq / L, Cl 100 mg / dL, because metabolic alkalosis with normal anion gap is characteristic.

Output: 3


Input: Consider Input: Question: Epidemiology allows early detection of changes in the incidence of a certain disease in the population. For this, the most correct thing is to use: 
 Options:  <1> The etiological investigation. <2> The description of the natural history of the disease. <3> Epidemiological surveillance. <4> The evaluation of the functioning of the services. <5> None of the previous answers is correct.

Output: 3


Input: Consider Input: Question: When we inject 1 nanoliter (nL) sample we are referring to the injection of: 
 Options:  <1> 10-1 L. <2> 10-3 L. <3> 10-6 L. <4> 10-9 L. <5> 10-12 L.


Output: 4