Task: Question Understanding
Input (English): Passage: Lévis returned to France on parole, and was released for service in Europe by William Pitt. He served in the German campaigns of 1762, and retired from active military service when the war ended in 1763 with the Peace of Paris. He was appointed governor of Artois in 1765. He was promoted to Marshal of France in 1783, and was raised to the inheritable title Duc de Lévis in 1784. He died in 1787 in Arras, France, and was succeeded as duke of Lévis by his son Pierre-Marc-Gaston, who escaped to England during the French Revolution. His widow and three daughters were sent to the guillotine during the French Revolution. He left his name to Lévis, Quebec, across the river from Quebec City.
Question: How many years after serving in the German campaigns did Lévis etired from active military service?
Output (English): number