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 Go (1.6) (judge verdict: Accepted)

// Package main provides
//
// File:  c.go
// Author: ymiyamoto
//
// Created on Thu Jan 10 09:47:06 2019
//
package main

import "fmt"

func main() {
	var H, W, N int
	fmt.Scan(&H, &W, &N)
	arr := make([]int, N)
	for i := range arr {
		fmt.Scan(&arr[i])
	}

	board := make([][]int, H)
	for i := range board {
		board[i] = make([]int, W)
	}

	h, w := 0, 0
	for i := range arr {
		for arr[i] > 0 {
			board[h][w] = i + 1
			w++
			if w == W {
				h++
				w = 0
			}
			arr[i]--
		}
	}

	for i := range board {
		if i%2 == 0 {
			for j := range board[i] {
				if j != 0 {
					fmt.Print(" ")
				}
				fmt.Print(board[i][j])
			}
		} else {
			for j := len(board[i]) - 1; j >= 0; j-- {
				if j != len(board[i])-1 {
					fmt.Print(" ")
				}
				fmt.Print(board[i][j])
			}
		}
		fmt.Println()
	}
}