You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[2-[4-(2-pyridin-3-yloxyacetyl)piperazin-1-yl]ethyl]thiophene-3-carboxamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H22N4O3S
assistant