output_description: If E869120 can pay exactly N yen using only his 1-yen and 500-yen coins, print
  `Yes`; otherwise, print `No`.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N
      A
attempt: H, W = map(int, input().split())
  s = [[i for i in input()] for i in range(H)]
  maze = [[False for i in range(W)] for i in range(H)]
  bknum = 0
  for i in range(H):
      for j in range(W):
          if s[i][j] == ".":
              maze[i][j] = True
          else:
              maze[i][j] = False
              bknum += 1
  
  
  def ncell(i, j):
      tmp = [[i - 1, j], [i + 1, j], [i, j - 1], [i, j + 1]]
      out = []
      for p in tmp:
          if 0 <= p[0] < H and 0 <= p[1] < W and maze[i][j]:
              out.append(p)
      return out
  
  
  d = [[1000 for j in range(W)] for i in range(H)]
  prev = [[-1 for j in range(W)] for i in range(H)]
  d[0][0] = 0
  Q = set()
  for i in range(H):
      for j in range(W):
          if maze[i][j]:
              Q.add(i * W + j)
  while len(Q) != 0:
      u = list(Q)[0]
      du = d[u // W][u % W]
      for v in Q:
          if d[v // W][v % W] < du:
              du = d[v // W][v % W]
              u = v
      Q -= set([u])
      for v in ncell(u // W, u % W):
          if d[v[0]][v[1]] > d[u // W][u % W] + 1:
              d[v[0]][v[1]] = d[u // W][u % W] + 1
              prev[v[0]][v[1]] = u
  length = d[H - 1][W - 1]
  if length != 1000:
      print(H * W - length - 1 - bknum)
  else:
      print(-1)
  
problem_description: Statement
  
  E869120 has A 1-yen coins and infinitely many 500-yen coins.  
  Determine if he can pay exactly N yen using only these coins.
samples: [{"input": "2018\n    218", "output": "Yes\n    \n\nWe can pay 2018 yen with four 500-yen coins and 18 1-yen coins, so the answer\nis `Yes`.\n\n* * *"}, {"input": "2763\n    0", "output": "No\n    \n\nWhen we have no 1-yen coins, we can only pay a multiple of 500 yen using only\n500-yen coins. Since 2763 is not a multiple of 500, we cannot pay this amount.\n\n* * *"}, {"input": "37\n    514", "output": "Yes"}]