题解 | #快速排序#

attr = input()
attr2lst = [i for i in attr]
def qucik_sort(attr):
    if len(attr) < 2:
        return attr
    else:
        pivot = 0
        less = [
            attr[i] for i in range(1, len(attr)) if ord(attr[i]) <= ord(attr[pivot])
        ]
        more = [attr[i] for i in range(1, len(attr)) if ord(attr[i]) > ord(attr[pivot])]
        return qucik_sort(less) + [attr[pivot]] + qucik_sort(more)
lst2attr = ""
for i in qucik_sort(attr2lst):
    lst2attr += i
print(lst2attr)