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-[4-(4-amino-8-methyl-5-oxo-7,8-dihydropyrimido[5,4-f][1,4]oxazepin-6-yl)phenyl]cyclopentane-1-carboxamide .
user
C20H23N5O3
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