# Problem 7

Algebra Level 5

$\frac{H}{K+A}+\frac{K}{H+A}+\frac{A}{H+K}+S\frac{HK+KA+HA}{H^2+K^2+A^2}\geq S+\frac{3}{2}$

Given that $$H,K,A$$ are non-negative. Find the maximum positive real of $$S$$.