1551: Codeforce934A-A Compatible Pair

Nian is a monster which lives deep in the oceans. Once a year, it shows up on the land, devouring livestock and even people. In order to keep the monster away, people fill their villages with red colour, light, and cracking noise, all of which frighten the monster out of coming.

Little Tommy has n lanterns and Big Banban has m lanterns. Tommy's lanterns have brightness a₁, a₂, ..., a_n, and Banban's have brightness b₁, b₂, ..., b_m respectively.

Tommy intends to hide one of his lanterns, then Banban picks one of Tommy's non-hidden lanterns and one of his own lanterns to form a pair. The pair's brightness will be the product of the brightness of two lanterns.

Tommy wants to make the product as small as possible, while Banban tries to make it as large as possible.

You are asked to find the brightness of the chosen pair if both of them choose optimally.

The first line contains two space-separated integers n and m (2 ≤ n, m ≤ 50).

The second line contains n space-separated integers a₁, a₂, ..., a_n.

The third line contains m space-separated integers b₁, b₂, ..., b_m.

All the integers range from  - 10⁹ to 10⁹.

2 2
20 18
2 14

252