ABC problem

ABC problem is a draft programming task. It is not yet considered ready to be promoted as a complete task, for reasons that should be found in its talk page.

You are given a set of ABC blocks. Just like the ones you had when you were a kid. There are twenty blocks with two letters on each block. You are guaranteed to have a complete alphabet amongst all sides of the blocks. The sample blocks are:

((B O)

(X K)

(D Q)

(C P)

(N A)

(G T)

(R E)

(T G)

(Q D)

(F S)

(J W)

(H U)

(V I)

(A N)

(O B)

(E R)

(F S)

(L Y)

(P C)

(Z M))

The goal of this task is to write a function that takes a string and can determine whether you can spell the word with the given set of blocks. The rules are simple:

1. Once a letter on a block is used that block cannot be used again
2. The function should be case-insensitive

Example

<lang python>

   >>> can_make_word("")
   False
   >>> can_make_word("A")
   True
   >>> can_make_word("BARK")
   True
   >>> can_make_word("BOOK")
   False
   >>> can_make_word("TREAT")
   True
   >>> can_make_word("COMMON")
   False
   >>> can_make_word("SQUAD")
   True

</lang>