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 Python (3.4.3) (judge verdict: Accepted)

def solve(H, W, N, As):
    # print(H, ",", W, ",", N, ",", As)
    field = [[0] * W for _ in range(H)]
    index = 0
    for color, a in enumerate(As):
        color += 1
        for _ in range(a):
            row = index // W
            if row % 2 == 0:
                field[row][index - row * W] = str(color)
            else:
                field[row][W - (index - row * W) - 1] = str(color)
            index += 1
    ans = "\n".join([" ".join(row) for row in field])
    return ans


# print(solve(2, 2, 3, [2, 1, 1]))

if __name__ == "__main__":
    H, W = tuple(map(int, input().split(" ")))
    N = int(input())
    As = list(map(int, input().split(" ")))
    print(solve(H, W, N, As))