[Maximum Two Word Solution] Suppose, you have devised an algorithm to find out the password for the enigma machine. However, your algorithm needs to solve n files group by group in order to find out that password. Your algorithm can not solve a group if, files from previous groups are not solved, and if it starts to solve a group before its previous groups are solve then the program crashes and millions of people die as a result. Moreover, a group may need multiple groups to be solved before it can be solved. Each file consists of some characters required for the decryption. If each group has m files then which algorithm will you use as a submodule so that you avoid the worse case for your program.