output_description: Print the largest integer that can be formed with exactly N matchsticks under
  the conditions in the problem statement.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N M
      A_1 A_2 ... A_M
attempt: N, M = map(int, input().split())
  A = list(map(int, input().split()))
  
  AtoH = [0, 2, 5, 5, 4, 5, 6, 3, 7, 6]
  H = [AtoH[a] for a in A]
  # print("H:", H)
  
  dp = [0] * (N + 1)
  dpl = [0] * (N + 1)
  
  for i in range(M):
      h, a = H[i], A[i]
      dp[N - h] = max(dp[N - h], dp[N] + a)
      dpl[N - h] = 1
  
  for dpi in range(N - 1, -1, -1):
      if dp[dpi]:
          for m in range(M):
              h, a = H[m], A[m]
              if dpi - h >= 0:
                  if dp[dpi - h] < dp[dpi] + 10 ** dpl[dpi] * a:
                      dp[dpi - h] = dp[dpi] + 10 ** dpl[dpi] * a
                      dpl[dpi - h] = dpl[dpi] + 1
  print(dp[0])
  
problem_description: Statement
  
  Find the largest integer that can be formed with exactly N matchsticks, under
  the following conditions:
  
    * Every digit in the integer must be one of the digits A_1, A_2, ..., A_M (1 \leq A_i \leq 9).
    * The number of matchsticks used to form digits 1, 2, 3, 4, 5, 6, 7, 8, 9 should be 2, 5, 5, 4, 5, 6, 3, 7, 6, respectively.
samples: [{"input": "20 4\n    3 7 8 4", "output": "777773\n    \n\nThe integer 777773 can be formed with 3 + 3 + 3 + 3 + 3 + 5 = 20 matchsticks,\nand this is the largest integer that can be formed by 20 matchsticks under the\nconditions.\n\n* * *"}, {"input": "101 9\n    9 8 7 6 5 4 3 2 1", "output": "71111111111111111111111111111111111111111111111111\n    \n\nThe output may not fit into a 64-bit integer type.\n\n* * *"}, {"input": "15 3\n    5 4 6", "output": "654"}]