Given the following passage  "Four boarders at his parents' apartments became Chopin's intimates: Tytus Woyciechowski, Jan Nepomucen Białobłocki, Jan Matuszyński and Julian Fontana; the latter two would become part of his Paris milieu. He was friendly with members of Warsaw's young artistic and intellectual world, including Fontana, Józef Bohdan Zaleski and Stefan Witwicki. He was also attracted to the singing student Konstancja Gładkowska. In letters to Woyciechowski, he indicated which of his works, and even which of their passages, were influenced by his fascination with her; his letter of 15 May 1830 revealed that the slow movement (Larghetto) of his Piano Concerto No. 1 (in E minor) was secretly dedicated to her – "It should be like dreaming in beautiful springtime – by moonlight." His final Conservatory report (July 1829) read: "Chopin F., third-year student, exceptional talent, musical genius."",  answer the following question. Note that the answer is present within the text.  Question: How did they become his friends?
A:
boarders at his parents' apartments