查找列表中重复的数字

def FRN(nums):
    ls = set()
    k = set()
    for i in nums:
        if i in ls:
            k.add(i)
            print('k:', k)
        else:
            ls.add(i)
            print('ls', ls)
    return sorted(k)


a = list(map(int, input().split()))
print(list(FRN(a)))