In this task, you're given a passage, further information available on a particular linked term from the statement, and an answer term. Your job is to generate a question that can use the information provided to obtain the given answer. You should use the information on both passage and link information to create the question. Note that the answer to the question should be exactly the given answer, and if the answer is none, the answer to the question shouldn't be obtainable from the passage or linked information.
Q: Passage: Ivan Mihailov was born on 26 August 1896, in the village of Novo Selo (now part of Stip Municipality, North Macedonia) in the Kosovo Vilayet of the Ottoman Empire. Mihailov studied at the Bulgarian Men's High School in Thessaloniki up until the Second Balkan War when the school was closed by the new Greek administration, he later continued his studies at a Serbian school in Skopje. He was offered a scholarship by the Serbian Ministry of Education to pursue a degree at a European university but declined, later enlisting in the Bulgarian army, which had by that time occupied a significant portion of the region. After the end of World War I, Mihailov emigrated to Bulgaria, settling in Sofia. Here he began studying law at the Sofia University, at which time he was contacted by IMRO activists and offered to work as a personal secretary for IMRO's leader at that time, Todor Aleksandrov.
Link Information: Mihailov studied at the Bulgarian Men's High School in Thessaloniki up until the Second Balkan War when the school was closed by the new Greek administration, Answer: 17
A:
How old was Mihailov when the Second Blakan War began?