You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-(2,3-dihydro-1,4-benzodioxin-3-ylmethyl)-3-[2-(4-pyrazol-1-ylphenyl)ethyl]urea is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H22N4O3
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