def numUniqueChars( word ):
	"""
	Determine how many letters of the alphabet are present in a given word.

	@param word An English word.
	@returns The number of unique letters in that word.
	"""
	seen = ['\n']
	count = 0

	for c in word:
		if c not in seen:
			count += 1
			seen.append( c )

	return count