题解 | #删除字符串中出现次数最少的字符#

def inputstr():
    str1 = input('')
    while True:
        if len(str1) < 0 or len(str1) >20:
            str1 = input('')
        else:
            str1.lower()
            return str1
    

def delMinCont(str1):
    strCount = []
    strlist = []
    for i in str1:
        strCount.append(str1.count(i))
        strlist.append(i)
    # print(strCount)
    # print(strlist)
    index = 0
    for i in strCount:
        
        if i == min(strCount):
            # print(i)
            # print(strlist[index])
            # 删除操作的时候索引会向前移动一位，所以此时index不用+1
            del strlist[index]
            continue
        index =index + 1
        # print(index)
    return ''.join(strlist)


str1 = inputstr()

print(delMinCont(str1))