Blocks

Our hero Kim has now managed to work his way through the cells, and arrives at the main vault of the entire operation. However, this vault is guarded by a password protected door, and what's more, the password seems to be of some length $N$ ($1 \leq N \leq 10^6$)! Kim absolutely must get to the vault, in order to see what sorts of treasures Soum may be hiding. But, the issue is, he doesn't know