妖梦拼木棒

def solve(lengths):
    from collections import Counter
    lengths = list(map(int, lengths.split(',')))
    count = Counter(lengths)
    total = 0
    for l in count:
        if count[l] >= 2:
            pairs = count[l] * (count[l] - 1) // 2
            for other in count:
                if other < l:
                    total += pairs * count[other]
    print(total)