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 Java (OpenJDK 11.0.6) (judge verdict: Accepted)

import java.util.*;

public class Main {

	public static void main(String[] args) {
		Main main = new Main();
		main.run();
	}

	int a[];
	int color;
	public void run() {
		Scanner sc = new Scanner(System.in);
		int h=sc.nextInt();
		int w=sc.nextInt();
		int n=sc.nextInt();
		a = new int[n];
		color=0;
		for(int i=0; i<n; i++) {
			a[i]=sc.nextInt();
		}

		int ans[][] = new int[h][w];
		for(int i=0; i<h; i++) {
			if(i%2==0) {
				for(int j=0; j<w; j++) {
					ans[i][j]=nextc();
				}
			}else {
				for(int j=w-1; j>=0; j--) {
					ans[i][j]=nextc();
				}
			}
		}
		for(int i=0; i<h; i++) {
			for(int j=0; j<w; j++) {
				if(j>0)System.out.print(" ");
				System.out.print(ans[i][j]);
			}
			System.out.println();
		}
		sc.close();
	}

	public int nextc() {
		if(a[color]==0) {
			color++;
		}
		a[color]--;
		return color+1;
	}



}