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#F2782. Deletion of Repeats

    ID: 2788 传统题 2000ms 256MiB 尝试: 0 已通过: 0 难度: 7 上传者: 标签>贪心哈希后缀结构算法思想数据结构字符串提高难度共享题库Codeforces英文题面题目来源题面语言

Deletion of Repeats

题目描述

C. Deletion of Repeats
time limit per test
2 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output

Once Bob saw a string. It contained so many different letters, that the letters were marked by numbers, but at the same time each letter could be met in the string at most 10 times. Bob didn't like that string, because it contained repeats: a repeat of length x is such a substring of length 2x, that its first half coincides character by character with its second half. Bob started deleting all the repeats from the string. He does it as follows: while it's possible, Bob takes the shortest repeat, if it is not unique, he takes the leftmost one, and deletes its left half and everything that is to the left of this repeat.

You're given the string seen by Bob. Find out, what it will look like after Bob deletes all the repeats in the way described above.

Input

The first input line contains integer n (1≤n≤105) − length of the string. The following line contains n space-separated integer numbers from 0 to 109 inclusive − numbers that stand for the letters of the string. It's guaranteed that each letter can be met in the string at most 10 times.

Output

In the first line output the length of the string's part, left after Bob's deletions. In the second line output all the letters (separated by a space) of the string, left after Bob deleted all the repeats in the described way.

Examples
Input
6
1 2 3 1 2 3
Output
3
1 2 3
Input
7
4 5 6 5 6 7 7
Output
1
7

题目来源:fps-www.educg.net-codeforce-1-2833.xml.zip;FPS 共享题包,题包内第 2452 题。保留原作者与原赛事署名。