Example of mass derivation for one of the sources. Left panels: 1 Myr isochrone (solid red line) combined from the PARSEC and BT-Settl models at 1 M_⊙ mass (Bressan et al. 2012; Chen et al. 2014; Baraffe et al. 2015) and the source with its error bars (solid orange cross). The grey dots represent the generated magnitude points from 1000 runs. In the first panel, a line parallel to the extinction vector would show where the mass lies on the model. In the second panel, the dotted red lines are parallel to the reddening vectors. Red crosses mark the extinction in 5 mag steps from 0 to 15 mag. Right panels: mass and extinction distribution, respectively, obtained from 1000 runs.