def solve(words):
    score = 0
    forbidden = set()
    for k in [(50 - i) for i in range(50)]:
        for i in words:
            for j in words:
                if i[-k:] == j[-k:] and i != j and i[-k:] not in forbidden:
                    forbidden.add(i[-k:])
                    score += 2
                    words.remove(i)
                    words.remove(j)
    return score

#-------
t = int(input())
for i in range(t):
    numwords = int(input())
    wordlist = []
    for j in range(numwords):
        wordlist.append(str(input()))
    print ("Case #" + str(i+1) + ": " + str(solve(wordlist)))