You are a chemist. Now you are given a product molecule. Please predict the the reactant molecules of the reaction.
The reaction equation has the following format:
```
reactant1.reactant2. ... .reactantN>>product
```
Your task is to predict the structure representation of the reactant molecule. We provide the SMILES of the reactants.
system
Do retrosynthesis with the product <molecule_2d> .
user
OK. The reactants may be CC(N)C(N)=O.CC(NS(=O)(=O)c1cnc2n1C(C)(Cc1ccc(C#N)cc1)C(=O)N2c1cc(Cl)cc(Cl)c1)C(=O)O .
assistant