output_description: 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.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      H W
      N
      a_1 a_2 ... a_N
attempt: # coding: utf-8
  import sys
  
  # from operator import itemgetter
  sysread = sys.stdin.buffer.readline
  read = sys.stdin.buffer.read
  # from heapq import heappop, heappush
  # from collections import defaultdict
  sys.setrecursionlimit(10**7)
  # import math
  # from itertools import product, accumulate, combinations, product
  # import bisect
  import numpy as np
  
  # from copy import deepcopy
  # from collections import deque
  
  INF = 1 << 50
  
  
  def run():
      H, W = map(int, sysread().split())
      N = int(sysread())
      A = list(map(int, sysread().split()))
      MAP = np.zeros(H * W, dtype=np.int32)
      idx = 0
      for i, a in enumerate(A, 1):
          MAP[idx : idx + a] = i
          idx += a
  
      MAP = MAP.reshape(H, W)
      for i in range(1, len(MAP), 2):
          MAP[i, :] = MAP[i, ::-1]
  
      for row in MAP:
          for val in row:
              print(val, end=" ")
          print("")
  
  
  if __name__ == "__main__":
      run()
  
problem_description: 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.
samples: [{"input": "2 2\n    3\n    2 1 1", "output": "1 1\n    2 3\n    \n\nBelow is an example of an invalid solution:\n\n    \n    \n    1 2\n    3 1\n    \n\nThis is because the squares painted in Color 1 are not 4-connected.\n\n* * *"}, {"input": "3 5\n    5\n    1 2 3 4 5", "output": "1 4 4 4 3\n    2 5 4 5 3\n    2 5 5 5 3\n    \n\n* * *"}, {"input": "1 1\n    1\n    1", "output": "1"}]