P26256 [AtCoder] Make Same Set
NOI
题目描述

Problem Statement

You are given three integer sequences of length N: $A=(A_1,A_2,\dots,A_N),B=(B_1,B_2,\dots,B_N),C=(C_1,C_2,\dots,C_N)$.
Find one set of integers that satisfies the following conditions.

  • It can be obtained as follows: start with an empty set, and for each $i=1,2,\dots,N$ in this order, add A_i or B_i to the set.
  • It can be obtained as follows: start with an empty set, and for each $i=1,2,\dots,N$ in this order, add A_i or C_i to the set.
  • It has the maximum number of elements among the sets that satisfy the two conditions above.

Input

The input is given from Standard Input in the following format:
N
$A_1 A_2 \dots A_N$
$B_1 B_2 \dots B_N$
$C_1 C_2 \dots C_N$

Output

Print k, the number of elements in the set of integers satisfying the conditions, and x_i\ $(1\leq i \leq k)$, the k elements of the set, in the following format:
k
$x_1 x_2 \dots x_k$

If multiple sets satisfy the conditions, you may print any of them.

Constraints

  • $1 \leq N \leq 5000$
  • $1 \leq A_i,B_i,C_i \leq 10000$
  • All values in the input are integers.

Sample Input 1

3
1 1 1
2 3 4
5 4 2

Sample Output 1

3
4 1 2

For the set $\lbrace 1,2,4\rbrace$, we have the following.

  • The first condition is satisfied because you can add B_1,A_2,B_3 to an empty set to obtain this set.
  • The second condition is satisfied because you can add A_1,C_2,C_3 to an empty set to obtain this set.

Clearly, any set satisfying these conditions has at most N=3 elements, so this set also satisfies the third condition.

Sample Input 2

15
1 1 15 11 13 7 7 1 6 1 5 7 4 9 8
11 30 1 18 16 15 19 17 3 27 22 7 21 29 9
24 14 23 17 18 16 9 12 10 5 26 29 20 19 11

Sample Output 2

12
7 9 11 17 19 1 15 4 5 6 29 13

输入格式

见题面 Input 部分

输出格式

见题面 Output 部分

样例输入
3 1 1 1 2 3 4 5 4 2
样例输出
3 4 1 2