Specific three-loop contributions to b → sγ associated with the current-current operators

We work out a specific class of three-loop diagrams (of order $\alpha_s^2$) contributing to the decay amplitude for $b \to s \gamma$ associated with current-current operators $O_1$ and $O_2$ at physical value charm-quark mass $m_c$. For many considered we were able solve master integrals using differential equations in canonical form. some did not find transformation form therefore calculated corresponding integral directly as an expansion around $z=m_c^2/m_b^2=0$, retaining power terms up $z^{10}$ keeping accompanying $\log(z)$ all powers. The results sum are given tabular form, while contributions individual (or combinations thereof) electronic