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# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Text;
using System.Collections.Generic;
using System.Linq;
class Solve{
    public Solve(){}
    StringBuilder sb;
    public static int Main(){
        new Solve().Run();
        return 0;
    }
    void Run(){
        sb = new StringBuilder();
        Calc();
        Console.Write(sb.ToString());
    }
    void Calc(){
        string[] str = Console.ReadLine().Split(' ');
        int H = int.Parse(str[0]);
        int W = int.Parse(str[1]);
        int N = int.Parse(Console.ReadLine());
        str = Console.ReadLine().Split(' ');
        int[] A = new int[N];
        for(int i=0;i<N;i++){
            A[i] = int.Parse(str[i]);
        }
        int[,] C = new int[H,W];
        int p = 0;
        for(int i=0;i<H;i++){
            for(int j=0;j<W;j++){
                if(A[p] == 0){
                    p++;
                }
                if(i%2 == 0){
                    C[i,W-1-j] = p+1;
                }
                else{
                    C[i,j] = p+1;
                }
                A[p]--;
            }
        }
        for(int i=0;i<H;i++){
            for(int j=0;j<W;j++){
                sb.Append(C[i,j]);
                if(j == W-1){
                    sb.Append("\n");
                }
                else{
                    sb.Append(" ");
                }
            }
        }
    }
}