Hertzsprung-Russell diagram with all the evolutionary tracks and the best-fit seismic models of the five HADS. The coloured solid evolutionary tracks show the stages from the zero-age main sequence (ZAMS) to the post-main sequence (post-MS) evolutionary phase, with initial masses covering 1 M_⊙. The regions surrounded by the black rectangular boxes are zoomed-in views of the best-fit seismic models, represented by red stars. The coloured dashed lines indicate evolutionary tracks with initial mass steps of 0.01 M_⊙.