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 PHP (7.4.4) (judge verdict: Accepted)

<?php
  list($h,$w) = explode(" ", trim(fgets(STDIN)));
  list($n) = explode(" ", trim(fgets(STDIN)));
  $a = explode(" ", trim(fgets(STDIN)));

  $ans = [];
  for($i=0;$i<$h;$i++){
    $ans[$i]=[];
    for($j=0;$j<$w;$j++){
      $ans[$i][$j] = 0;
    }
  }
  $count=0;
  $v = [];
  for($i=0;$i<count($a);$i++){
    for($j=0;$j<$a[$i];$j++){
      $v[$count]=$i+1;
      $count++;
    }    
  }

  $y = 0;
  $x = 0;
  $count = 0;
  $dir = 0; // 0:down, 1:right; 2:up; 3:left
  for($i=0;$i<$h*$w;$i++){
    $ans[$y][$x] = $v[$count];
    $count++;
    if($dir == 0){
      if($y+1 >= $h || $ans[$y+1][$x]!=0){
        $dir = 1;
        $x++;
      }else{
        $y++;
      }
    }else if($dir == 1){
      if($x+1 >= $w || $ans[$y][$x+1]!=0){
        $dir = 2;
        $y--;
      }else{
        $x++;
      }
    }else if($dir == 2){
      if($y == 0 || $ans[$y-1][$x]!=0){
        $dir = 3;
        $x--;
      }else{
        $y--;
      }
    }else{
      if($x == 0 || $ans[$y][$x-1]!=0){
        $dir = 0;
        $y++;
      }else{
        $x--;
      }
    }  
  }
  for($i=0;$i<$h;$i++){
    echo implode(" ", $ans[$i]);
    echo PHP_EOL;
  }