You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 5-methyl-N-[2-(7-methyl-5-oxo-[1,3]thiazolo[3,2-a]pyrimidin-3-yl)ethyl]-1-phenylpyrazole-4-carboxamide into its molecular formula.
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C20H19N5O2S
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