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: Accepted)

#include<iostream>
#include<stdio.h>
#include<string.h>
#include<algorithm>
#include<vector>
#include<queue>
#include<map>
#include<set>
#include<iomanip>
#include<cmath>


#define REP(i,n) for (int i = 0; (i) < (n); ++ (i))
#define FOR(i,n) for (int i = 1; (i) <= (n); ++ (i))
#define dump(x)  cout << #x << " = " << (x) << endl;
#define pb push_back
#define int long long
//#define lint long long

const int INF = 1e9;
const int MOD = 1e9+7;
//const lint LINF = 1e18;
const double eps = 0.000000001;//もとの値の10^(-16)まで

using namespace std;

//typedef pair<int, int> P;
int h,w,n;
int a[200000];
int ans[200][200];
signed main(){
  cin >> h >> w >> n;
  REP(i,n) cin >> a[i];
  int now = 0;
  int zan = 0;
  REP(i,h){
    REP(j,w){
      if(zan == 0){
        zan = a[now];
        now ++;
      }
      if(i%2==0){
        ans[i][j] = now;
      }
      else{
        ans[i][w-1-j] = now;
      }
      zan --;
    }
  }
  REP(i,h){
    REP(j,w-1){
      cout << ans[i][j] << " ";
    }
    cout << ans[i][w-1] << endl;
  }
  return 0;
}