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