题解 | #字符统计#用sorted套娃

while True:
    
    try:
        str_input = input()
        new_list = list(set(str_input))
        str_dict = {}
        for c in new_list:
            str_dict[c] = str_input.count(c)
        res_list = sorted(sorted(str_dict.items(), key=lambda x : x[0]), key=lambda y: y[1], reverse=True)
        result = ''
        for i in res_list:
            result += i[0]
        print(result)
        
        
    except:
        break