$\mathcal{H-}$ and $\mathcal{R-}$cross-sections of the full finite semigroup $T_n$

All $\mathcal{H}-$ and $\mathcal{R}-$ cross-sections of the full finite semigroup $T_n$ of all transformations of the set $N=\{1,2,\ldots,n\}$ are described.