This is not humanly possible. Respirators are absolutely necessary for any long term -and sometimes even short term- survival for climbers to the top of Mt. Everest; Not even the native Sherpa's live near its peak.
It's 36in. long because if you multiply 12 and 3 you will get 36!
Approximately 1 foot - 12 inches
A foot (plural: feet) is 12 inches or about 30 cm.
12 inches
39,375 inches = 3,281.25 feet.