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 Kotlin (1.0.0) (judge verdict: Accepted)

import java.util.*

fun main(args: Array<String>) {
    val scanner = Scanner(System.`in`)
    val H = scanner.nextInt()
    val W = scanner.nextInt()
    val N = scanner.nextInt()

    val c = IntArray(H*W)
    var curIndex = 0
    for (i in 1..N) {
        val noc = scanner.nextInt()
        for (j in 1..noc) {
            c[curIndex] = i
            curIndex++
        }
    }

    val builder = StringBuilder()
    for (i in 0 until H) {
        builder.append(if (i%2==0) c.copyOfRange(i*W,(i+1)*W).toStringWithSpace() else c.copyOfRange(i*W,(i+1)*W).reversedArray().toStringWithSpace()).append("\n")
    }
    print(builder.toString())
}

fun IntArray.toStringWithSpace(): String {
    val builder = StringBuilder()
    this.forEach { builder.append(it).append(" ") }
    return builder.removeSuffix(" ").toString()
}