You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-(4-phenylphenyl)-2-spiro[21-thia-10-azapentacyclo[11.8.0.03,11.04,9.015,20]henicosa-1(13),2,4,6,8,11,15,17,19-nonaene-14,9'-fluorene]-10-yl-[1]benzofuro[3,2-d]pyrimidine The above is the IUPAC name of a molecule. Write its molecular formula.
user
C53H31N3OS
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