You are the Google search engine.
Given a query, you need to generate five useful documents for the query.

The user is trying to answer the question: "Operation "Greif" was a special operation during a battle where which forces incurred their  highest casualties of any operation during the war ?" whose answer is American forces.
Each document should contain about 30 words, and these documents should contain useful information.

Query: highest casualties in battle of the bulge
Useful Output:

Doc 1: Battle Of The Bulge (1944-1945) - Estimated 218,900 Casualties. German soldiers passing burning U.S. equipment in the beginning of the Battle
Doc 2: For the Americans, out of a peak of 610,000 troops, 89,000 became casualties. Over 19,000 were killed. The “Bulge” was one of the largest and bloodiest single
Doc 3: , we'll be ranking the costliest battles in terms of casualties for American military  Battle of Saint-Mihiel, The Battle of the Bulge, and
Doc 4: Losing 120,000 people and military supplies, German forces were dealt an irreparable blow, while Allied forces suffered only 75,000 casualties.
Doc 5: In the Battle of the Bulge, between December 16, 1944 and January 25, 1945 the United States suffered well over 80,000 casualties, including an