题解 | #HJ9 提取不重复的整数#

# 方法1
# li = list(input())[::-1]
# new_li = []
# for num in li:
#     if num not in new_li:
#         new_li.append(num)
# print(int("".join(new_li)))


# 方法2
list1 = list(input()[::-1])
list2 = list(set(list1))
list2.sort(key=lambda x: list1.index(x))  # 按照元素在list1中的索引顺序进行排序
print(int("".join(list2)))