Q: In this task, you're given a statement, further information available on a particular linked term from the statement, and a question. Your job is to generate the answer to the question by using the information provided. If there is no clear answer obtainable, output 'none'.
Context: effort to investigate as many archaeological sites as possible in the area that would be flooded by Lake Assad, the reservoir of the Tabqa Dam, which was being built at that time. Link Information: The dam was constructed between 1968 and 1973 Question: When did the construction of the dam that flooded Mureybet begin?
A:
Answer: 1968