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>
#include<stdlib.h>

#define MAX_H 100
#define MAX_W 100

int h, w;
int n;
int a[MAX_H * MAX_W];

int int_sort( const void* c1, const void* c2 )
{
	int a1 = *(int *)c1;
	int a2 = *(int *)c2;
	
	if ( a1 < a2 ) return -1;
	if ( a1 > a2 ) return 1;
	return 0;
}
int main(void)
{
	int num, a_num;
	int i, j;
	
	scanf( "%d %d %d", &h, &w, &n );
	
	a_num = 0;
	for( i=1; i<=n; i++ ) {
		scanf( "%d", &num );
		for( j=0; j<num; j++ ) {
			a[a_num++] = i;
		}
	}
	
	qsort( a, n, sizeof(a[0]), int_sort );
	for( i=0; i<h; i++ ) {
		if ( i % 2 == 0 ) {
			for( j=0; j<w; j++ ) {
				printf( "%d", a[i*h+j] );
			}
		}
		else {
			for( j=0; j<w; j++ ) {
				printf( "%d", a[i*h+(w-j)] );
			}
		}
		putchar( '\n' );
	}
	
	return 0;
}