题解 | #删除字符串中出现次数最少的字符#

import sys

#for line in sys.stdin:
#    a = line.split()
 #   print(int(a[0]) + int(a[1]))
s = input()

dict1 = {}
for i in s:
    if i not in dict1:
        dict1[i]=1
    else:
        dict1[i]+=1
#print(dict1.items())
dict1 = sorted(dict1.items(),key=lambda x:x[1])
#print(dict1)
min=dict1[0][1]
func=lambda x : x[1]==min
dict1= filter(func,dict1)
res =''
#print()
s=list(s)
for i in dict1:
    j,k =i[0],i[1]
    #print(j)
    #print(j)
    #s.remove(j)
    s=filter(lambda x :x!=j,s)
    s=list(s)
print(''.join(s))