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
<molecule_2d> Given the product provided, propose some possible reactants that could have been employed in its formation.
user
Here are possible reactants: Cn1cc(-c2cnc3nnn(CC4CN(c5ncc(-c6cnn(C7CCNCC7)c6)cn5)CCO4)c3n2)cn1.OCCBr .
assistant