题解 | #字符统计#

list1=list(input())
list1.sort()
list2=[]

#print(list1)   ['a', 'a', 'c', 'c', 'c', 'd', 'd', 'd']

for i in list1:
    if i not in list2: list2.append(i)
    else: continue
#print(list2)   ['a', 'c', 'd']
    
list3=[]   
for i in list2:
    list4=[]
    list4.append(i)
    list4.append(list1.count(i))
    list3.append(list4)
    
#print(list3)   [['a', 2], ['c', 3], ['d', 3]]
list3.sort(key=lambda x:x[1],reverse=True)

for i in list3:
    print(i[0],end='')
#华为od#