reduced and the Anderson theorem is violated. This may have serious repercussions on the *s-wave superconductivity* in $1ML$ $FeSe/SrTiO_{3}$ (and $1ML$ $FeSe/TiO_{2}$) where $T_{c0}$ may depend on chemistry. Then by using equation $Eq.$(\[Tc-s-wave\]) from Appendix one obtains $T_{c}^{(s)}$$$\frac{T_{c}^{(s)}}{T_{c0}}=\frac{4}{\pi^{2}\rho}\psi(\frac{1}{2}+\frac{\rho
}{2})-\psi(\frac{1}{2}),$$ where $\rho=\Gamma/\pi T_{c}$, $\Gamma=\pi n_{i}N(E_{F})u^{2}$, $n_{i}$ is the impurity concentration and $u$ is the impurity potential. Let us consider some limiting cases: ($1$) for $\Gamma\ll\pi T_{c}^{(s)}$one has $T_{c}^{(s)}\approx T_{c0}[1-7\zeta(3)\Gamma/\pi^{3}T_{c0}]$; ($2$) for $\Gamma
\gg\pi T_{c}$ one has $T_{c}^{(s)}\approx(\Gamma/2\pi)\exp(-\pi\Gamma
/4T_{c0})$, i.e. $T_{c}^{(s)}$ never vanishes. This means that in the $EPI-FSP$ systems the non-magnetic impurity scattering is *pair-weakening* for the s-wave superconductivity.

In the case of *d-wave superconductivity* the solution of $Eq.$(\[Tc-d-wave\]) in limiting cases is:  ($1$) $T_{c}^{(d)}\approx
T_{c0}[1-2\Gamma/\pi T_{c0}]$ for $\Gamma\ll\pi T_{c}^{(d)}$. We point out that the slope $-dT_{c}^{(d)}/d(\Gamma)=2/\pi$ is smaller than the slope for the standard $d$-wave pairing, where $-dT_{c}/d(\Gamma)=\pi/4$. ($2$)  For $\Gamma>\Gamma_{cr}^{(FSP)}\approx(4/\pi)T_{c0}$ one has $T_{c}^{(d)}=0$, i.e. the effect of non-magnetic impurities is *pair-breaking*. Note, that $\Gamma_{cr}^{(FSP)}>\Gamma_{cr}(=(2/\pi)T_{c0})$. These two results mean that in the presence of non-magnetic impurities the $d$-wave superconductivity which is due to the $EPI-FSP$ pairing is more robust than in the case of the standard $d$-wave pairing. We stress, that the $T_{c}$ dependence on non-magnetic impurities in $1ML$ $FeSe/SrTiO_{3}$ 