Problem:
Score : 400 points

Problem Statement

We have a grid with H rows and W columns of squares.
Snuke is painting these squares in colors 1, 2, ..., N.
Here, the following conditions should be satisfied:

For each i (1 ≤ i ≤ N), there are exactly a_i squares painted in Color i. Here, a_1 + a_2 + ... + a_N = H W.

For each i (1 ≤ i ≤ N), the squares painted in Color i are 4-connected. That is, every square painted in Color i can be reached from every square painted in Color i by repeatedly traveling to a horizontally or vertically adjacent square painted in Color i.

Find a way to paint the squares so that the conditions are satisfied.
It can be shown that a solution always exists.

Constraints

1 ≤ H, W ≤ 100

1 ≤ N ≤ H W

a_i ≥ 1

a_1 + a_2 + ... + a_N = H W

Input

Input is given from Standard Input in the following format:

H W
N
a_1 a_2 ... a_N

Output

Print one way to paint the squares that satisfies the conditions.
Output in the following format:

c_{1 1} ... c_{1 W}
:
c_{H 1} ... c_{H W}

Here, c_{i j} is the color of the square at the i-th row from the top and j-th column from the left.

Sample Input 1

2 2
3
2 1 1

Sample Output 1

1 1
2 3

Below is an example of an invalid solution:

1 2
3 1

This is because the squares painted in Color 1 are not 4-connected.

Sample Input 2

3 5
5
1 2 3 4 5

Sample Output 2

1 4 4 4 3
2 5 4 5 3
2 5 5 5 3

Sample Input 3

1 1
1
1

Sample Output 3

1

Solution in Ruby (2.3.3) (judge verdict: Accepted)

class MASS
  def initialize(h, w)
    @h = h
    @w = w
    @m = Array.new(@h){Array.new(@w, 0)}
    @x = 0
    @y = 0
    @LR = 1
  end
  def draw(v, n)
    n.times do |i|
      @m[@y][@x] = v + 1
      @x += @LR
      if @x == @w
        @y += 1
        @x = @w - 1
        @LR = -1
      elsif @x < 0
        @y += 1
        @x = 0
        @LR = 1
      end
    end
  end
  def out
    @h.times do |i|
      puts @m[i].join(' ')
    end
  end
end

h, w = gets.split.map(&:to_i)
n = gets.to_i
a = gets.split.map(&:to_i)
m = MASS.new(h, w)
a.each_with_index do |v, i|
  m.draw(i, v)
end
m.out