You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Under IUPAC nomenclature, a molecule named [(Z)-[3,5-difluoro-4-[4-(pyridin-3-ylmethyl)piperazin-1-yl]phenyl]methylideneamino]thiourea is given. What is its corresponding molecular formula?
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C18H20F2N6S
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