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 "fmt"
func main() {
  var h,w,n int
  fmt.Scan(&h,&w,&n)
  var a []int = make([]int,n)
  for i:=0;i<n;i++ { fmt.Scan(&a[i]) }
  var c [][]int = make([][]int,h)
  for i:=0;i<h;i++ { c[i] = make([]int,w) }
  var x,y,dy,k int
  dy = 1
  for a[n-1] > 0 {
    c[x][y] = k+1
    a[k]--
    if a[k] == 0 { k++ }
    y += dy
    if y == w {
      x++
      y = w-1
      dy = -1
    } else if y == -1 {
      x++
      y = 0
      dy = 1
    }
  }
  for i:=0;i<h;i++ {
    fmt.Print(c[i][0])
    for j:=1;j<w;j++ {
      fmt.Print(" ")
      fmt.Print(c[i][j])
    }
    fmt.Println()
  }
}