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(void){
	int H,W,N,tail=0;
	scanf("%d %d",&H,&W);
	scanf("%d",&N);
	int a[N],c[H][W];
	int queue[10001];
	for(int i=0;i<N;i++){
		scanf("%d",&a[i]);
	}
	for(int i=0;i<N;i++){
		for(int j=0;j<a[i];j++){
			queue[tail] = i+1;
			tail++;
		}
	}
			tail=0;
	for(int j=0;j<H-1;j++){
		for(int i=0;i<W;i++){
			if(j%2 ==0){
			printf("%d",queue[j*W+i]);
			}else{
				printf("%d",queue[j*W-i+W-1]);
			}
		}
			printf("\n");
	}
		for(int i=0;i<W;i++){
			if((H-1)%2 ==0){
			printf("%d",queue[(H-1)*W+i]);
			}else{
				printf("%d",queue[(H-1)*W-i+W-1]);
			}
		}
	return 0;
}