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)-1-ethyl-3-(1-methyl-4,5,6,7-tetrahydroindazol-4-yl)urea is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H26N4O3
assistant