Greatest Common Increasing Subsequence

You are given two sequences of integer numbers. Write a program to determine their common increasing subsequence of maximal possible length.
Sequence S₁ , S₂ , . . . , S_N of length N is called an increasing subsequence of a sequence A₁ , A₂ , . . . , A_M of length M if there exist 1 <= i₁ < i₂ < . . . < i_N <= M such that S_j = A_ij for all 1 <= j <= N , and S_j < S_j+1 for all 1 <= j < N .

Each sequence is described with M --- its length (1 <= M <= 500) and M integer numbers A_i (-2³¹ <= A_i < 2³¹ ) --- the sequence itself.

On the first line of the output file print L --- the length of the greatest common increasing subsequence of both sequences. On the second line print the subsequence itself. If there are several possible answers, output any of them.

5
1 4 2 5 -12
4
-12 1 2 4

2
1 4