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 <bits/stdc++.h>

#ifndef LOCAL_
#define fprintf if( false ) fprintf
#endif // LOCAL_
#define dump() fprintf(stderr, "#%s.%d\n", __func__, __LINE__);
#define dumpl(x1) fprintf(stderr, "#%s.%d (%s) = (%ld)\n", __func__, __LINE__, #x1, x1);
#define dumpll(x1, x2) fprintf(stderr, "#%s.%d (%s, %s) = (%ld, %ld)\n", __func__, __LINE__, #x1, #x2, x1, x2);
#define dumplll(x1, x2, x3) fprintf(stderr, "#%s.%d (%s, %s, %s) = (%ld, %ld, %ld)\n", __func__, __LINE__, #x1, #x2, #x3, x1, x2, x3);
#define dumpd(x1) fprintf(stderr, "#%s.%d (%s) = (%lf)\n", __func__, __LINE__, #x1, x1);
#define dumpdd(x1, x2) fprintf(stderr, "#%s.%d (%s, %s) = (%lf, %lf)\n", __func__, __LINE__, #x1, #x2, x1, x2);
#define loop for(;;)
typedef std::vector<long> LI;
typedef std::queue<long> QI;
#define rep(i,n) for(long i = 0; i < (long)n; ++i)
const double pi = M_PI;
const long mod = 1000000007;

template<typename T> void scan1(T& x) { fprintf(stderr, "unknown type\n"); }
template<> void scan1(long& x) { if( scanf("%ld", &x) < 0 ) exit(0); }
template<> void scan1(std::string& x) { if( not ( std::cin >> x ) ) exit(0); }
void scan() {}
template<typename Head, typename... Tail>
void scan(Head& x, Tail&... xs) {
  scan1(x); scan(xs...);
}

struct Solver {
   Solver() { fprintf(stderr, "--------Solver begin--------\n"); }
   ~Solver() { fprintf(stderr, "--------Solver end--------\n"); }
   long field[128][128];
   void solve() {
      for(long i = 0; i < 128; ++i) {
         for(long k = 0; k < 128; ++k) {
            field[i][k] = 0;
         }
      }
      long h, w; scan(h, w);
      long n; scan(n);
      LI xs(n); for(long &x : xs) scan(x);
      long dx[4] = {0, 0, 1, -1};
      long dy[4] = {1, -1, 0, 0};
      long x = 0, y = 0;
      long c = 0;
      loop {
         field[y][x] = c + 1;
         xs[c] -= 1;
         if( xs[c] == 0 ) c += 1;
         if( c == n ) break;
         for(long k = 0; k < 4; ++k) {
            long nx = x + dx[k], ny = y + dy[k];
            if( not ( 0 <= nx and nx < w and 0 <= ny and ny < h ) ) continue;
            if( field[ny][nx] != 0 ) continue;
            x = nx, y = ny;
            break;
         }
         dumplll(c, x, y);
      }
      for(long i = 0; i < h; ++i) {
         printf("%ld", field[i][0]);
         for(long k = 1; k < w; ++k) {
            printf(" %ld", field[i][k]);
         }
         putchar('\n');
      }
   }
};

int main() {
   loop std::unique_ptr<Solver>(new Solver())->solve();
}