Mr. X runs a marathon starting from the point A he runs 5 km towards north and reach point B, then turns right runs 6 km reach point C, then turn light runs 8 km and reach point D, then turns right runs 10 km and reach point E, then turns right runs 6 km and reach point F, then turns right runs 1 km and reach point G, then turn rights runs 3 km and reach point H.
The shortest distance between point D and G is?