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.Collections.Generic;
using System.Linq;

class Program
{
    static string InputPattern = "InputX";

    static List<string> GetInputList()
    {
        var WillReturn = new List<string>();

        if (InputPattern == "Input1") {
            WillReturn.Add("2 2");
            WillReturn.Add("3");
            WillReturn.Add("2 1 1");
            //1 1
            //2 3
        }
        else if (InputPattern == "Input2") {
            WillReturn.Add("3 5");
            WillReturn.Add("5");
            WillReturn.Add("1 2 3 4 5");
            //1 4 4 4 3
            //2 5 4 5 3
            //2 5 5 5 3
        }
        else if (InputPattern == "Input3") {
            WillReturn.Add("1 1");
            WillReturn.Add("1");
            WillReturn.Add("1");
            //1
        }
        else {
            string wkStr;
            while ((wkStr = Console.ReadLine()) != null) WillReturn.Add(wkStr);
        }
        return WillReturn;
    }

    static void Main()
    {
        List<string> InputList = GetInputList();

        int[] wkArr = InputList[0].Split(' ').Select(X => int.Parse(X)).ToArray();
        int H = wkArr[0];
        int W = wkArr[1];

        int[] AArr = InputList[2].Split(' ').Select(X => int.Parse(X)).ToArray();

        int UB_X = W - 1;
        int UB_Y = H - 1;

        int[,] BanArr = new int[UB_X + 1, UB_Y + 1];
        int CurrInd = 0;

        for (int Y = 0; Y <= UB_Y; Y++) {
            for (int X = 0; X <= UB_X; X++) {
                int TargetX = X;
                if (Y % 2 == 1) TargetX = UB_X - X;

                BanArr[TargetX, Y] = CurrInd + 1;
                AArr[CurrInd]--;
                if (AArr[CurrInd] == 0) {
                    CurrInd++;
                }
            }
        }

        var sb = new System.Text.StringBuilder();
        for (int Y = 0; Y <= UB_Y; Y++) {
            for (int X = 0; X <= UB_X; X++) {
                sb.Append(BanArr[X, Y]);
                if (X < UB_X) sb.Append(" ");
            }
            sb.AppendLine();
        }
        Console.Write(sb.ToString());
    }
}