题解 | #删除字符串中出现次数最少的字符#

str = input()
dic = {}
res = ''

# set() 是为了减少循环次数
for s in set(str): 
    cnt = str.count(s)
    dic[s] = cnt
    
for d in str :
    idx = min(dic.values())
    if dic[d] != idx :
        res += d 
print (res)