num=input() dict1={} # 1.统计字符个数,存放到dict中 for i in num: if i not in dict1: dict1[i]=1 else: dict1[i]=dict1[i]+1 # 2.提取字典value,存放到list1中 list1=[] for i in dict1.values(): list1.append(i) # 3.取出list1中的最小值 minnun=min(list1) # 4.从dict1中取出最小值对应的key,放到list2中 list2=[] for i in dict1: if dict1[i]==minnun: list2.append(i) # 5.遍历字符串,如果字母不是最小值(也就说不是在list2中),则输出 str1='' for i in num: if i not in list2: str1=str1+i print(str1)