47th: (b) 2 close, 3 open, 1 close, 2 open, 3 close, 1 open, 1 close, 1 open, 7 close, 9 open, 4 close, (a) 4 open, 2 close, 1 open, 3 close, X 1 open, 2 close, X twice, 1 open, 3 close, 7 open.
48th: (b) 2 close, 5 open, 3 close, 1 open, X 2 close, 1 open, X twice, 3 close, 9 open, 4 close, (a) 6 open, 1 close, 1 open, 3 close, 1 open, 2 close, 1 open, 1 close, 2 open, 2 close, 9 open.
49th: (b) 2 close, 4 open, X 3 close, 1 open, X twice, 2 close, 13 open, 4 close, (a) 7 open, 1 close, 1 open, 6 close, 2 open, 3 close, 9 open.
50th: 2 close, 4 open, 2 close, 1 open, 4 close, 1 open, 2 close, 7 open, 1 close, 5 open, 3 close, (a) 8 open, 2 close, 1 open, 3 close, 2 open, 1 close, 1 open, 2 close, 11 open.
51st: (b) 2 close, 4 open, 4 close, 1 open, 2 close, 1 open, 3 close, 5 open, 2 close, 6 open, 3 close, (a) 8 open, 2 close, 3 open, 3 close, 1 open, 1 close, 11 open.
52nd: (b) 2 close, 5 open, X 2 close, 2 open, X twice, 3 close, 3 open, 3 close, (a) 19 open, 3 close, 1 open, 1 close, 23 open.
53rd: (b) 2 close, 6 open, 3 close, 2 open, 3 close, 2 open, 7 close, (a) 49 open.
54th: (b) 2 close, 10 open, 3 close, 4 open, 4 close, (a) 49 open.
55th: (b) 2 close, 11 open, 9 close, (a) 51 open.
56th: (b) 2 close, 12 open, 7 close (a) 53 open.