Posterior distribution of the distance to the lens D_L and its mass M_L for the ground+Gaia+Spitzer model (red solid contours) and the ground+Gaia model (blue dashed contours). The shaded areas show the 1, 2, and 3σ contours for each of the solutions. As the u₀ parameter is known to be negative from C21, only u₀ < 0 solutions are shown here. The additional clump at D_L ≈ 4.5 kpc is caused by irregularities in source distance distribution calculated in B21.