Table:
text: Mazurkas (Chopin)
List of mazurkas
List of mazurkas
Series_number Key_ Composed Published Opus_No_ Brown Kobylańska Chominski Dedication Notes_
47 Am 1827 1855 Op. posth. 68/2 B. 18  C. 97  
48 F 1829 1855 Op. posth. 68/3 B. 34  C. 98  Quotes the folk tune Oj, Magdalino
46 C 1829 1855 Op. posth. 68/1 B. 38  C. 96  
49 Fm 1849 (summer) 1855 Op. posth. 68/4 B. 168  C. 99  Chopin`s last composition; first published in an incomplete form 1855
– C 1833 1870 – B. 82 KK IVb/3 P 2/3  
– D 1829 1875 – B. 31 KK IVa/7 P 1/7  Heavily revised 1832 (see B. 71, KK IVb/2; rev. vers. pub. 1880)

Question: What is the serial number of the piece called "Chopin's Last Composition" under Mazurkas (Chopin)?