Dieckmann Decarboxylation

Q. In the following reaction sequence, the correct structures of (E), (F) and (G) are:

(*implies ${}^{13}C$ labelled carbon)

1. 
2. 
3. 
4. 

Q. $N{H}_3$ reacts with a gas fumes produced when methanol is passed through $Cu$ tube at $573K$. The compound obtained is polycyclic. How many rings does it contain= [X]. The number of nitrogen atoms it has = [Y]? Report your answer as X+Y.