题解 | #字符统计#

import sys



'''
接收字符串
'''

s = list(input())

def Mycount(s):
    '''
    定义字典存储字符的出现次数，利用count函数统计字符出现次数
    '''
    dict1={}

    s2 =list(set(s))
    for x in s2:
        dict1[x]=s.count(x)
   #关键是排序函数要有2个条件，先针对值降序排序，再针对键升序排序
    L =list(sorted(dict1.items(),key=lambda x:( -x[1],x[0])))
    for x in L:
        print(x[0],end="")

Mycount(s)