A record store receives n vinyl records for its back catalog; each record is stamped with an integer catalog code, and the same code can appear on more than one record when a title was pressed multiple times. The stockroom's numbered shelves, starting at shelf 1, follow one strict rule: a single shelf may never hold two records that share a catalog code. Copies of the same code are always shelved in encounter order -- the first copy of a code goes on shelf 1, the second copy of that same code goes on shelf 2, the third goes on shelf 3, and so on, so a code that appears c times ends up occupying shelves 1 through c (one copy per shelf) and never touches shelf c + 1 or beyond.

Given the codes for all n records, determine how many shelves this rule requires in total, and, for every shelf from 1 up to that total, which catalog codes sit on it.

Input format

• Line 1: an integer n, the number of records.
• Line 2: n integers, the catalog codes of the records, space-separated.

Output format

• Line 1: a single integer B, the total number of shelves used.
• The next B lines: for shelf j (1 <= j <= B), a line with the number of codes on that shelf, followed by those codes listed in increasing order, all space-separated.

Constraints

• 1 <= n <= 10^5
• 1 <= catalog code <= 10^9

7
1 3 4 1 2 3 1

3
4 1 2 3 4
2 1 3
1 1

4
5 2 9 1

1
4 1 2 5 9