For strong electrolyte $$\lambda_m$$ increases slowly with dilution and can be represented by the equation
$$\Lambda_m = \Lambda_m^\circ - A c^{1/2}$$
Molar conductivity values of the solutions of strong electrolyte AB at 18°C are given below:

The value of constant A based on the above data [in S $$cm^{2}mol^{-1}/(mol/L)^{1/2}$$]unit is_______.