Replicate data over adjacent servers
Severs
A B C D
doc -> Server B # Needs have 2 copies
[A,B], [B,C]

Severs
A    B    C    D
2mb  3mb  4mb  2mb

x = how many copies a doc needs to have

What is the biggest document you can have x copies of
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Input:
  Two arrays A and B
  Lower and Upper

 Find the total number of pairs of elements where one element is from A and the other is from B such that
 lower <= A^2 + B^2 <= upper

Ex)
A = [1,2,3]
B = [1,2,3] [1,4,9]
lower = 3
upper = 13

ans = 7 # (1,2),(2,1),(1,3),(3,1),(2,2),(2,3),(3,2)