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: Accepted)

#include <stdio.h>

int main(int argc, char *argv[])
{
	int i, j, H, W, HW[100][100] = {{0}};
	int N, h = 0, w = 0, s = 0; /* 0: -> 1: <- */
	scanf("%d %d", &H, &W);
	scanf("%d", &N);
	for ( i = 0; i < N; i++ ){
		int a;
		scanf("%d", &a);
		if ( s == 0 ){
			for ( ; w < W; w++, a-- ){
				if ( a == 0 ){
					break;
				}
				HW[h][w] = i+1;
			}
			if ( w == W ){
				h++;
				w = W-1;
				s = 1;
			}
		} else {
			for ( ; w >= 0; w--, a-- ){
				if ( a == 0 ){
					break;
				}
				HW[h][w] = i+1;
			}
			if ( w < 0 ){
				h++;
				s = 0;
				w = 0;
			}
		}
		if ( a == 0 ){
			continue; /* この行はなくてもOK */
		}
		while ( a/W > 0 ){
			for ( j = 0; j < W; j++ ){
				HW[h][j] = i+1;
			}
			h++;
			a -= W;
			s = 0;
			w = 0;
		}

		if ( s == 0 ){
			for ( ; w < W; w++, a-- ){
				if ( a == 0 ){
					break;
				}
				HW[h][w] = i+1;
			}
		} else {
			for ( ; w >= 0; w--, a-- ){
				if ( a == 0 ){
					break;
				}
				HW[h][w] = i+1;
			}
		}
	}
	for ( h = 0; h < H; h++ ){
		for ( w = 0; w < W; w++ ){
			printf("%d%s", HW[h][w], w==W-1?"\n":" ");
		}
	}
	return 0;
}