You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[ethyl-[3-[1-(4-methyl-1,3-thiazol-2-yl)ethylcarbamoylamino]cyclobutyl]amino]acetic acid is the IUPAC name of a molecule. Please give its molecular formula.
user
C15H24N4O3S
assistant