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 Java8 (OpenJDK 1.8.0) (judge verdict: Runtime Error)

import java.io.PrintWriter; 
import java.util.Scanner; 

public class Main
{
	static Scanner in; 
	static PrintWriter out; 

	static void solve()
	{ 
		int H = in.nextInt();
		int W = in.nextInt(); 
		int N = in.nextInt(); 
		int[] a = new int[N]; 
		String S = "";
		for(int i = 0; i < N; i++) 
		{ 
			a[i] = in.nextInt(); 
		} 
		for (int i = 0; i < a.length; i++) 
		{ 
			for(int j = 0; j < a[i]; j++)
			{ 
				S += i + 1;
			}
		} 
		for (int i = 0; i < H; i++) 
		{ 
			for(int j = 0; j < W; j++)
			{ 
				if (j != 0)
				{ 
					out.print(" "); 
				} 
				if(i % 2 == 0)
				{ 
					out.print(S.charAt(W*i+j-1)); 
				}
				else
				{ 
					out.print(S.charAt(W*i+(W-1)-j-1));      
				} 
			} 
			out.println(); 
		} 
	} 

	public static void main(String[] args) 
	{ 
		in = new Scanner(System.in); 
		out = new PrintWriter(System.out); 
		solve(); 
		out.flush(); 
		out.close(); 
		in.close(); 
	} 
}