$f(x) = x^{8}+15 x^{7}+5 x^{6}-1297 x^{5}-8573 x^{4}+1249 x^{3}+154827 x^{2}+260033 x^{1} - 406260$

What is the maximum number of positive real roots for $f(x)$?
What is the maximum number of negative real roots for $f(x)$?