KöMaL 2023 B5335

The product of the positive numbers $x$, $y$, $z$ is 1. What may be the value of the expression $\left(x+\frac{1}{x}\right)^{2} +\left(y+\frac{1}{y}\right)^{2} +\left(z+\frac{1}{z}\right)^{2} -\left(x+\frac{1}{x}\right) \left(y+\frac{1}{y}\right) \left(z+\frac{1}{z}\right)?$