* L0: Input/Output (I/O), text formatting
* L1: Static libraries
* L2: Arrays and pointers, "asignación de memoria exacta" (stack memory) (*)
* L3: "asignación de memoria dinamica" (heap memory) (**)
* L4: Generic (void) pointers
* L5: 
* LA: past mid-term exam solution
* E1: 
* L6: 
* L7: 
* L8: 
* L9: 
* L10: 
* E2: 

Opinion on difficulty:
(*): hard to do in 2h
(**): very hard to do in 2h