You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the SMILES notation for 2-(2-ethylsulfonylpropan-2-ylsulfonyl)butylphosphonic acid ?
user
CCC(CP(=O)(O)O)S(=O)(=O)C(C)(C)S(=O)(=O)CC
assistant