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 JavaScript (node.js v5.12) (judge verdict: Accepted)

inp = require('fs').readFileSync('/dev/stdin', 'utf8').trim().split('\n')
l = inp.shift().split(' ')
H = l.shift() * 1
W = l.shift() * 1 
N = inp.shift() * 1
ans = []
for (i=0; i<H; i++) {
    ans[i] = new Array(W)
}

h = 0
w = 0
a = inp.shift().split(' ')
m = 'R'
for (i=0; i<N; i++) {
    n = a[i] * 1
    for (j=0; j<n; j++) {
        if (ans[h][w] === undefined) {
            ans[h][w] = i+1
        }

        if (w == W - 1 && m == 'R') {
            h++
            m = 'L'
        } else if (w === 0 && m == 'L') {
            h++
            m = 'R'
        } else if (m == 'R') {
            w++
        } else if (m == 'L') {
            w--
        }
    }
}
console.log(ans.map(a => a.join(' ')).join('\n'))