TASK DEFINITION: Generate a correct and concise answer for the question based on the words in the context.
PROBLEM: Context : Karl Gustav von Sandrart (1817-1898) was a Prussian general in the Franco-Prussian War of 1870. 
Question : In what war did Karl Gustav von Sandrart fight?

SOLUTION: Franco-Prussian War

PROBLEM: Context : Rear Admiral Charles Stillman Sperry (3 September 1847 -- 1 February 1911) was an officer in the United States Navy. 
Question : Which military did Charles Stillman Sperry serve with?

SOLUTION: United States Navy

PROBLEM: Context : Multi-party elections have been held since 1992, although a democratically elected government was ousted in the 1997 Republic of the Congo Civil War and President Denis Sassou Nguesso has ruled for 26 of the past 36 years. 
Question : Which person was the head of government of Republic of the Congo?

SOLUTION:
Denis Sassou Nguesso