Even diameters of the classes $W^{(r)}H_\omega$ in the space $C_2\pi$

For even values of $n$ we find the exact values of the diameters $d_n(W^{(r)}H_\omega)$ of the classes of $2\pi$-periodic functions $W^{(r)}H_\omega$ ($\omega(t)$ is an arbitrary convex upwards modulus of continuity) in the space $C_2\pi$. We find that $d_{2n}(W^{(r)}H_\omega)$ ($n=1,2,\dots$; $r=0,1,2,\dots$).