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 C (GCC 5.4.1) (judge verdict: Wrong Answer)

#include<stdio.h>

int main()
{
 int H, W, N;
 int grid[10005];
 int a[10005];
 int i,j;
 int colors[10005];
 int count=0;
 int temp;

 scanf("%d %d",&H,&W);
 scanf("%d",&N);

 for(i=0;i<N;i++)
 {
  scanf("%d",&a[i]);
  for(j=0;j<a[i];j++) 
  { 
    colors[count]=i+1;
    count++;
  }
 }

 for(j=0;j<H;j++)
 {
  if(j%2 == 0)
  {
   for(i=0;i<W;i++) grid[i+j*W] = colors[i+j*W];
  }else{
   for(i=0;i<W;i++) grid[(j+1)*W-1-i] = colors[i+j*W];
  }
 }

 for(j=0;j<H;j++)
 {
  for(i=0;i<W;i++) printf("%d",grid[i+j*W]);
  printf("\n");
 }

 return 0;
}