You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Friedrich_Hayek

Context:
Friedrich August von Hayek was born in Vienna to August von Hayek and Felicitas Hayek (née von Juraschek). Friedrich's father, from whom he received his middle name, was also born in Vienna in 1871. He was a medical doctor employed by the municipal ministry of health, with passion in botany, in which he wrote a number of monographs. August von Hayek was also a part-time botany lecturer at the University of Vienna. Friedrich's mother was born in 1875 to a wealthy, conservative, land-owning family. As her mother died several years prior to Friedrich's birth, Felicitas gained a significant inheritance which provided as much as half of her and August's income during the early years of their marriage. Hayek was the oldest of three brothers, Heinrich (1900–69) and Erich (1904–86), who were one-and-a-half and five years younger than him.

Question:
How many children did August von Hayek and his wife have?

three