International Conference Seating Arrangement

There are representatives from \(m\) different organizations attending an international conference. The \(i\)-th organization sends \(r_i\) representatives.

The conference restaurant has \(n\) tables. The \(j\)-th table has a capacity of \(c_j\) persons.

To promote communication, no two representatives from the same organization are allowed to dine at the same table. Your task is to produce a seating arrangement that satisfies these requirements.

Note:

• For each organization, its representatives must be seated at different tables (i.e. at most one representative per table).
• For each table, the total number of seated representatives cannot exceed its capacity \(c_j\).
• You may assume that a valid seating arrangement exists.

inputFormat

The input is given as follows:

 m n
 r1 r2 ... rm
 c1 c2 ... cn

Where:

• \(m\) is the number of organizations.
• \(n\) is the number of tables.
• \(r_i\) is the number of representatives from organization \(i\) (1-based).
• \(c_j\) is the capacity of table \(j\) (1-based).

outputFormat

Output \(n\) lines. The \(j\)-th line describes the seating for table \(j\) in the following format:

 k a1 a2 ... ak

Where \(k\) is the number of representatives seated at table \(j\) and each \(a_l\) is the 1-based index of the organization of a seated representative. If no one is seated at a table, output a line containing 0.

sample

3 3
2 1 1
2 1 1

2 1 2
1 1
1 3

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