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
To synthesis <molecule_2d>, what are the possible reactants? Write in the SMILES representation.
user
O=[N+]([O-])c1cc(C23CC4CC(C2)CC(C25CC6CC(CC(C6)C2)C5)(C4)C3)cc(-c2cc(C34CC5CC(C3)CC(C36CC7CC(CC(C7)C3)C6)(C5)C4)cc([N+](=O)[O-])c2O)c1O
assistant