what you going to do to the unsold token?
All unsold tokens of current phase will be carried away to the next phase.
For me, guess this is a good strategy to get into your target token sales and also to utilize the allocated tokens for your ICO. Also, I see no reason burn the unsold tokens after each phase as PeruCoin has only 2,000,000 supply. I am pretty sure this will have a big impact on token's price.