[en] The procedure is introduced to construct Jost matrix on the S matrix of the second order. The procedure can be easily realised in numerical calculations. No simplifying supposition on the S matrix is imposed. S matrix reconstructed on our Jost matrice has the same phase shifts as the primary one does. The problem of the correct description of mixing angle function is reduced to minimization procedure. Our procedure is explained using the example of the S matrix of triplet np scattering. Numerical results are listed for this case