Given the task definition and input, reply with output. 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.

Question: In 1970 which university had more students, Princeton University or American University in Cairo? Passage 1:"Off the Books" is the third single from Stone Crazy, a 1997 album by East Coast hip hop group The Beatnuts. It was released by Relativity Records in both 12 inch and CD format in 1997. The song is produced by The Beatnuts and features raps by Juju and Psycho Les, the first on-record performance by Cuban Link, and a notable early verse from Big Punisher. (Big Pun's first on-record performance was the B-Side to Fat Joe's "Envy" single, "Firewater" with Fat Joe, Raekwon and Armageddon.) Lyrics from Psycho Les's verse were later sampled in "The Rep Grows Bigga" by Gang Starr and two Beatnuts songs: "No Escapin' This" and "Slam Pit". The track's beat samples "Break that Party and Opening" by Melvin Van Peebles, "Sign Song" by Buddy Baker, "Get out of My Life, Woman" by George Semper and "Hihache" by Lafayette Afro Rock Band.
Passage 2:Beinin was raised as a Zionist in an American Jewish family. On graduating from high school, he spent six months working on a kibbutz, where he met his future wife. He studied Arabic at university, and received his B.A. from Princeton University in 1970. He spent the summer of 1969 studying Arabic at the American University in Cairo. Intending to move to Israel permanently, he joined other members of Hashomer Hatzair in living and working at Kibbutz Lahav. There, on encountering attitudes that struck him as being contemptuous of Palestinians, he gradually became disenchanted with his early ideals. He returned to the United States in 1973, and took his M.A. from Harvard University in 1974, and, after working in auto plants in Detroit, obtained his A.M.L.S. and Ph.D. from the University of Michigan in 1978 and 1982, respectively. He has also studied at the Hebrew University of Jerusalem.
Passage 3:Throughout his club career, Pivatelli most notably played for A.C. Milan (196163); he also played for Hellas Verona F.C. (195053), Bologna F.C. 1909 (195360), and S.S.C. Napoli (196061). After being dropped from the Inter Youth Side, Pivatelli was acquired by Verona in 1950, with whom he made his Serie B debut at the age of 17, scoring his first professional goal in his second appearance with the club, in a 41 victory over Vicenza. The following season, he was promoted to the starting line-up, and scored a total of 25 goals in 68 games for his team during the next three seasons, also helping the struggling club avoid relegation. After joining Bologna in 1953, he made his Serie A debut with the club on 13 September 1953, in a 21 home win over Atalanta. With the Emilian side, he was the Serie A top-scorer during the 195556 Serie A season, with 29 league goals in 30 appearances, and was the only Italian player to win the Capocannoniere title during the 1950s. In total, he scored 105 goals for Bologna during his seven seasons with the club. After playing with Napoli for the 196061 season, he joined Milan in 1961, and was part of the side that won the Serie A title in 1962, and the European Cup in 1963 under manager Nereo Rocco, after which he subsequently retired from playing professional football.
2