You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[(4-ethylpyridin-2-yl)methyl]-3-[1-(1,3-thiazol-2-yl)piperidin-4-yl]urea is the IUPAC name of a molecule. Please give its molecular formula.
user
C17H23N5OS
assistant