The first and only line of input contains a single integer
, the requiring size of the set.
If there is no solution, print a single.
Otherwise, print a singlein the first line. The second line should contains
space-separated integers
, denoting the elements of the set. The integers must be pairwise distinct. It can be shown that if a solution exists, there must be a solution with all
.
After that, for eachfrom
to
, print a line to give out your division of subsets when the
-th element is deleted. The line should begin with a number
denoting the size of one of the subset, followed by
pairwise distinct integers
denoting the indices of elements of the subset.
must be held. The checker will automatically computes the other subset and check whether they have equal sums.
For the first example, it can be proved that there is no solution with.
For the second example,is an interesting set. For example, if you delete
from the set, you can divide the remaining set into
and
with
, and when deleting
from the set, we have
.
Note that you can printin arbitrary order, not necessarily sorted. The sample output above sorts them for better reading experience. The same goes for
.