Definition: In this task, you're given a question, along with three passages, 1, 2, and 3. Your job is to determine which passage can be used to answer the question by searching for further information using terms from the passage. Indicate your choice as 1, 2, or 3.
Input: Question: Who designed Hans Klemm's first light aircraft? Passage 1:The head of the femur, which articulates with the acetabulum of the pelvic bone, comprises two-thirds of a sphere. It has a small groove, or fovea, connected through the round ligament to the sides of the acetabular notch. The head of the femur is connected to the shaft through the neck or collum. The neck is 45cm. long and the diameter is smallest front to back and compressed at its middle. The collum forms an angle with the shaft in about 130 degrees. This angle is highly variant. In the infant it is about 150 degrees and in old age reduced to 120 degrees on average. An abnormal increase in the angle is known as coxa valga and an abnormal reduction is called coxa vara. Both the head and neck of the femur is vastly embedded in the hip musculature and can not be directly palpated. In skinny people with the thigh laterally rotated, the head of the femur can be felt deep as a resistance profound (deep) for the femoral artery.
Passage 2:Born in Tel Aviv, Israel, on November 26, 1971, Huberman is the son of Holocaust survivors. He and his family moved to Oak Ridge, Tenn., when his father, a cancer researcher, began working at the Oak Ridge National Laboratory. Huberman attended the University of WisconsinMadison, graduating with a Bachelor's Degree in psychology and English in 1994. After graduation, he joined the Chicago Police Department where he initially served as a beat officer. While working full-time as a Chicago police officer, Huberman attended night classes at the University of Chicago and earned two advanced degrees in 2000, a Master of Social Work from the School of Social Service Administration and a Master of Business Administration from the university's Graduate School of Business (now the Booth School of Business). Huberman was a recipient of The Paul & Daisy Soros Fellowships for New Americans and an Albert Schweitzer Fellow while attending the University of Chicago.
Passage 3:Hans Klemm's first light aircraft was the Daimler L15 and the L20 had much in common with it. Both were cantilever monoplanes with twin open, tandem cockpits and engines of very low power. The L20's low wing distinguished it from its predecessor and had the advantage of providing a low centre of gravity and better view during the landing approach as well as better protection for occupants in case of crash landings. The low-set wing also allowed a shorter undercarriage on the L20, which was otherwise like that of the L15 with the wheels independently mounted on pairs of centrally hinged V-struts and with vertical shock absorbing legs to the wing underside. Wheels were sometimes replaced by floats. Intended from the start for serial production, the L20's structure was simplified, with a pentagonal cross-section fuselage lacking the L15's rounded upper and lower surfaces. The fuselage was wooden framed with canvas covering. The overall strength of the structure, which had a safety factor of 12, was emphasised.

Output:
3