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++14 (GCC 5.4.1) (judge verdict: Runtime Error)

#include <iostream>
#include <string>

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define SafeDeleteArray(pData) { try { delete [] pData; } catch (...) { assert(false); } pData=NULL; }
typedef int aa[1000];
int  *a =new aa;
int b[100][100]={0};
int main()
{
    int H , W, n;
    cin >>H >>W;
    cin >>n;
    for(int i=1;i<=n;i++)
        cin >>a[i];
    int k=1;
    for(int j=1;j<=H;j+=2){
        for(int i=1;i<=W;i++){
            while(a[k]==0&&k<n)
                k++;
            b[j][i]=k;
            a[k]--;
        }
        if(j+1>H)
            break;
        for(int i=W;i>=1;i--){
            while(a[k]==0&&k<n)
                k++;
            b[j+1][i]=k;
            a[k]--;
        }
    }
    SafeDeleteArray(a);
    for(int i=1;i<=H;i++){
        for(int j=1;j<W;j++)
            cout<<b[i][j]<<" ";
        cout<<b[i][W]<<endl;
    }

    return 0;
}