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

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
)

var sc = bufio.NewScanner(os.Stdin)

func stringLineScan() string {
	sc.Scan()
	return sc.Text()
}

func main() {
	sc.Split(bufio.ScanWords)
	h, _ := strconv.Atoi(stringLineScan())
	w, _ := strconv.Atoi(stringLineScan())
	n, _ := strconv.Atoi(stringLineScan())
	c := 0
	ans := make([][]int, h)
	for i := 0; i < h; i++ {
		t := make([]int, w)
		ans[i] = t
	}
	for i := 1; i <= n; i++ {
		t, _ := strconv.Atoi(stringLineScan())
		for j := 0; j < t; j++ {
			ans[c/w][c%w] = i
			c++
		}
	}
	for i := 0; i < h; i++ {
		if i%2 == 0 {
			fmt.Println(strings.Trim(fmt.Sprint(ans[i]), "[]"))
		} else {
			t := make([]int, w)
			for j := 0; j < w; j++ {
				t[w-j-1] = ans[i][j]
			}
			fmt.Println(strings.Trim(fmt.Sprint(t), "[]"))
		}
	}
}