  In this paper we entertain a simple idea that the action of ghost free
massive gravity (in metric formulation) depends not on the full structure of
the square root of a matrix but rather on its invariants given by elementary
symmetric polynomials of the eigenvalues. In particular, we show how one can
construct the quadratic action around Minkowski spacetime without ever taking
the square root of the perturbed matrix. The method is however absolutely
generic. And it also contains full information on possible non-standard square
roots coming from intrinsic non-uniqueness of the procedure. In passing, we
mention some hard problems of those apocryphal square roots in the standard
approach which might be better tackled with our method. Futher details of the
latter are deferred to a separate paper.
