题解 | #删除字符串中出现次数最少的字符#

'''
解题思路：
通过in方法，按字典方法计算字符直方图，找到直方图最小值。最后遍历原输入，字符数超过最小时的输出。
'''
while 1:
    try:

        S = input().strip()
        S.lower()

        Dict = dict()
        for s in S:
            if s not in Dict:
                Dict[s] = 1
            else:
                Dict[s] += 1
        #print(Dict)

        Count = []
        for key in Dict:
            Count.append(Dict[key])
        i_min = min(Count)
        #print(i_min)

        Out = ''
        for s in S:
            if Dict[s] > i_min:
                Out += s
        print(Out)

    except:
        break