You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule 1-[(1S,12S)-7-(2-methoxyphenyl)-4,8,9,15-tetrazatetracyclo[10.2.1.02,10.05,9]pentadeca-2(10),3,5,7-tetraen-15-yl]ethanone .
user
C20H20N4O2
assistant