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)

h, w = gets.chomp.split(" ").map(&:to_i)
n = gets.chomp.to_i
a = gets.chomp.split(" ").map(&:to_i)

ans = Array.new(h).map{Array.new(w)}
ptr_h = 0
ptr_w = 0

a.each_with_index do |color_num, i|
    color_num.times do
        ans[ptr_h][ptr_w] = i+1
        if ptr_h % 2 == 0 then
            ptr_w += 1
        else
            ptr_w -= 1
        end
        if w <= ptr_w then
            ptr_h += 1
            ptr_w -= 1
        end
        if 0 > ptr_w then
            ptr_h += 1
            ptr_w += 1
        end
    end
end

ans.each do |res|
    puts res.join(" ")
end