T_{C},$ $G_{F}=\widetilde{\Omega
}/(\widetilde{\Omega }^{2}+\Phi _{F,\omega }\Phi _{F,-\omega }^{\ast
})^{1/2},$ $H$ is exchange energy, $\xi _{S,F}^{2}=(D_{S,F}/2\pi T_{C})$ and $D_{S,F},$ are diffusion coefficients in S and F metals, respectively. Pair potential $\Delta _{m}$ and the Usadel functions $\Phi _{m}$ and $\Phi
_{F}$ in (\[fiS\]) - (\[FiF\]) are also normalized to $\pi T_{C}.$ To write equations (\[fiS\]) - (\[FiF\]), we have chosen the $x$ axis in the directions perpendicular to the SI, FS and sF interfaces and put the origin at sF interface. Equations (\[fiS\]) - (\[FiF\]) must be supplemented by the boundary conditions [@KL]. At $x=-d_{s}$ they can be written as $$\begin{gathered}
G_{S}^{2}\frac{d}{dx}\Phi _{S}=G_{s}^{2}\frac{d}{dx}\Phi _{s},  \label{BCIF}
\\
\gamma _{BI}\xi _{S}G_{s}\frac{d}{dx}\Phi _{s}=-G_{S}\left( \Phi _{S}-\Phi
_{s}\right) ,  \notag\end{gathered}$$where $\gamma _{BI}=R_{BI}\mathcal{A}_{B}/\rho _{S}\xi _{S}$, $R_{BI}$ and $\mathcal{A}_{B}$ are resistance and area of SI interface. At $x=0$ the boundary conditions are$$\begin{gathered}
\frac{\xi _{S}}{\Omega }G_{s}^{2}\frac{d}{dx}\Phi _{s}=\gamma \frac{\xi _{F}}{\widetilde{\Omega }}G_{F}^{2}\frac{d}{dx}\Phi _{F},  \label{BCsF} \\
\gamma _{B}\xi _{F}G_{F}\frac{d}{dx}\Phi _{F}=-G_{s}\left( \frac{\widetilde{\Omega }}{\Omega }\Phi _{s}-\Phi _{F}\right)  \notag\end{gathered}$$and at $x=d_{F}$ they have the form $$\begin{gathered}
\frac{\xi _{S}}{\Omega }G_{S}^{2}\frac{d}{dx}\Phi _{S}=\gamma \frac{\xi _{F}}{\widetilde{\Omega }}G_{S}^{2}\frac{d}{dx}\Phi _{F},  \label{BCSF} \\
\gamma _{B}\xi _{F}G_{F}\frac{d}{dx}\Phi _{F}=G_{S}\left( \frac{\widetilde{\Omega }}{\Omega }\Phi _{S}-\Phi _{F}\right) ,  \notag\end{gathered}$$Far from the interfaces the solution should cross over to a uniform current-carrying superconducting state[@Ivanov]$^{-}$[@KuperD]$$\Phi _{S}(\mp \infty )=\Phi _{\infty 