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 C (GCC 5.4.1) (judge verdict: Wrong Answer)

#include<stdio.h>

int main(){
    int H, W, N, count = 0;
    int loop_bool = 0, loop_count = 0;
    int a[10000];
    int a_dash[10000];
    int c[100][100];
    scanf("%d%d", &H, &W);
    scanf("%d", &N);
    for(int i = 0; i < N; i++){
        scanf("%d", &a[i]);
        for(int j = 0; j < a[i]; j++){
            a_dash[count++] = i + 1;
        }
    }
    for(int i = 0, j = 0; i < count; i++){
        if(loop_bool == 0){
            c[j][loop_count] = a_dash[i];
            loop_count++;
            if(loop_count == W){
                loop_bool = 1;
                loop_count--;
                j++;
            }
        }else{
            c[j][loop_count] = a_dash[i];
            loop_count--;
            if(loop_count < 0){
                loop_bool = 0;
                loop_count++;
                j++;
            }
        }
    }
    for(int i = 0; i < H; i++){
        for(int j = 0; j < W; j++){
            printf("%d", c[i][j]);
        }
        puts("");
    }
    return 0;
}