“…13" respectively. The node pairs (1,2), (2,6), (3,4), (3,10), (4,15), (5,6), (7,5), (7,8), (7,9), (7,11), (7,20), (9,8), (9,11), (9,15), (10,13), (10,21), (11,16), (11,20), 12,18), (13,8), (13,22), (14,17), (14,22), (15,14), (15, 21), (15, 22), (16, 9), (16,14), (18, 16), (18, 17), (18, 20), (19,12), (19,16), (19,…”