write a go solution for Description:
To add insult to injury, the zombies have taken all but two drawings from Heidi! Please help her recover the Tree of Life from only these two drawings.

Input Format:
The input format is the same as in the medium version, except that now the bound on n is 2 ≤ n ≤ 1000 and that k = 2.

Output Format:
The same as in the medium version.

Note:
None. Output only the code with no comments, explanation, or additional text.