Passage: In spite of the failure of the German offensive to reach the 6th Army, the air supply operation continued under ever more difficult circumstances. The 6th Army slowly starved. General Zeitzler, moved by their plight, began to limit himself to their slim rations at meal times. After a few weeks on such a diet, he had "visibly lost weight", according to Albert Speer, and Hitler "commanded Zeitler to resume at once taking sufficient nourishment."The toll on the Transportgruppen was heavy. 160 aircraft were destroyed and 328 were heavily damaged (beyond repair). Some 266 Junkers Ju 52s were destroyed; one-third of the fleet's strength on the Eastern Front. The He 111 gruppen lost 165 aircraft in transport operations. Other losses included 42 Ju 86s, 9 Fw 200 Condors, 5 He 177 bombers and 1 Ju 290. The Luftwaffe also lost close to 1,000 highly experienced bomber crew personnel. So heavy were the Luftwaffe's losses that four of Luftflotte 4's transport units (KGrzbV 700, KGrzbV 900, I./KGrzbV 1 and II./KGzbV 1) were "formally dissolved."

Question: How many He 177 bombers were lost?
5