Detailed Instructions: In this task, you're given a context, 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 context 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 context or linked information.
Problem:Context: From Botevgrad to Sofia, E79 joins Hemus motorway, designated A2. Link Information: ts planned length is 424 km, of which 175 km are in operation . Answer: 424 km
Solution:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
How many Kilometres in total does the Hemus motorway measure?