题解 | #字符统计#

from sre_compile import isstring
string=input()
strings={}
for i in string:
        if i in strings:
            strings[i]+=1
        else:
            strings[i]=1


# 根据出现次数和 ASCII 码进行排序
# 默认升序，加负号变降序
sorted_strings = sorted(strings, key=lambda x: (-strings[x], ord(x)))
sorted_string = ''.join(sorted_strings)

print(sorted_string)