: gather
/^[[:space:]]*$/d
s/[[:space:]]\{1,\}/ /g
/.\{251\}/{
  s/^\(.\{6\}\)\(.\{6\}\)/     \1       \2\n1/;P
  s/^.*\n1\(.\{10\}\)\(.\{10\}\)/   \1   \2\n2/;P
  s/^.*\n2\(.\{13\}\)\(.\{13\}\)/ \1 \2\n3/;P
  s/^.*\n3\(.\{29\}\)/\1\n4/;P
  s/^.*\n4\(.\{29\}\)/\1\n5/;P
  s/^.*\n5\(.\{29\}\)/\1\n6/;P
  s/^.*\n6\(.\{27\}\)/ \1\n7/;P
  s/^.*\n7\(.\{23\}\)/   \1\n8/;P
  s/^.*\n8\(.\{19\}\)/     \1\n9/;P
  s/^.*\n9\(.\{15\}\)/       \1\nA/;P
  s/^.*\nA\(.\{11\}\)/         \1\nB/;P
  s/^.*\nB\(.\{7\}\)/           \1\nC/;P
  s/^.*\nC\(.\{3\}\)/             \1\nD/;P
  s/^.*\nD\(.\)/              \1\n/;P
  $ { d; q }
  D
}
$ { s/$/\./; b gather }
N
s/\n[^\n]/ /g
b gather