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: #!/usr/bin/env python3
  
  import sys
  
  # import math
  # from string import ascii_lowercase, ascii_upper_case, ascii_letters, digits, hexdigits
  # import re                                    # re.compile(pattern) => ptn obj; p.search(s), p.match(s), p.finditer(s) => match obj; p.sub(after, s)
  # from operator import itemgetter              # itemgetter(1), itemgetter('key')
  # from collections import deque                # deque class. deque(L): dq.append(x), dq.appendleft(x), dq.pop(), dq.popleft(), dq.rotate()
  # from collections import defaultdict          # subclass of dict. defaultdict(facroty)
  from collections import (
      Counter,
  )  # subclass of dict. Counter(iter): c.elements(), c.most_common(n), c.subtract(iter)
  
  # from heapq import heapify, heappush, heappop # built-in list. heapify(L) changes list in-place to min-heap in O(n), heappush(heapL, x) and heappop(heapL) in O(lgn).
  # from heapq import nlargest, nsmallest        # nlargest(n, iter[, key]) returns k-largest-list in O(n+klgn).
  # from itertools import count, cycle, repeat   # count(start[,step]), cycle(iter), repeat(elm[,n])
  # from itertools import groupby                # [(k, list(g)) for k, g in groupby('000112')] returns [('0',['0','0','0']), ('1',['1','1']), ('2',['2'])]
  # from itertools import starmap                # starmap(pow, [[2,5], [3,2]]) returns [32, 9]
  # from itertools import product, permutations  # product(iter, repeat=n), permutations(iter[,r])
  # from itertools import combinations, combinations_with_replacement
  # from itertools import accumulate             # accumulate(iter[, f])
  # from functools import reduce                 # reduce(f, iter[, init])
  # from functools import lru_cache              # @lrucache ...arguments of functions should be able to be keys of dict (e.g. list is not allowed)
  # from bisect import bisect_left, bisect_right # bisect_left(a, x, lo=0, hi=len(a)) returns i such that all(val<x for val in a[lo:i]) and all(val>-=x for val in a[i:hi]).
  from copy import copy, deepcopy  # to copy multi-dimentional matrix without reference
  
  # from fractions import gcd                    # for Python 3.4 (previous contest @AtCoder)
  
  
  def main():
      mod = 1000000007  # 10^9+7
      inf = float("inf")  # sys.float_info.max = 1.79...e+308
      # inf = 2 ** 64 - 1               # (for fast JIT compile in PyPy) 1.84...e+19
      sys.setrecursionlimit(10**6)  # 1000 -> 1000000
  
      def input():
          return sys.stdin.readline().rstrip()
  
      def ii():
          return int(input())
  
      def mi():
          return map(int, input().split())
  
      def mi_0():
          return map(lambda x: int(x) - 1, input().split())
  
      def lmi():
          return list(map(int, input().split()))
  
      def lmi_0():
          return list(map(lambda x: int(x) - 1, input().split()))
  
      def li():
          return list(input())
  
      n, m = mi()
      A = lmi()
      # A の前処理 (同じ必要本数なのに値が小さいやつらが入っていたら削除しておく)
      if 6 in A and 9 in A:
          A.remove(6)
      if 2 in A and 5 in A:
          A.remove(2)
      if 3 in A and 5 in A:
          A.remove(3)
      if 2 in A and 3 in A:
          A.remove(2)
  
      # 各数字とマッチの必要本数の対応テーブル
      num_to_match = {1: 2, 2: 5, 3: 5, 4: 4, 5: 5, 6: 6, 7: 3, 8: 7, 9: 6}
      match_to_num = dict()
      for num in A:
          match_to_num[num_to_match[num]] = num
  
      needed_match = [num_to_match[num] for num in A]
  
      # dp[i] = (指定された数字を使い i 本全部を使って作れる最大桁数, 使用数字のカウンタ)
      dp = [[None, None] for _ in range(n + 1)]
      dp[0][0] = 0
      dp[0][1] = Counter()
  
      def counter_gt(c1, c2):
          # print(f"{c1} {c2}")
          return sorted(tuple(c1.items()), key=lambda x: x[0], reverse=True) > sorted(
              tuple(c2.items()), key=lambda x: x[0], reverse=True
          )
  
      for i in range(n + 1):
          digit_max = 0
          counter_memo = None
          for match in needed_match:
              if i - match >= 0 and dp[i - match][0] is not None:
                  tmp = copy(dp[i - match][1])
                  tmp[match_to_num[match]] += 1
                  if dp[i - match][0] + 1 > digit_max or (
                      dp[i - match][0] + 1 == digit_max and counter_gt(tmp, counter_memo)
                  ):
                      digit_max = dp[i - match][0] + 1
                      counter_memo = copy(dp[i - match][1])
                      counter_memo[match_to_num[match]] += 1
  
          if digit_max != 0:
              dp[i][0] = digit_max
              dp[i][1] = counter_memo
  
      # print('')
      # for elm in dp:
      #     print(elm)
  
      char_array = [None] * dp[n][0]
      cnt = 0
      t = sorted(dp[n][1].items(), key=lambda x: x[0], reverse=True)
      for k, v in t:
          for i in range(v):
              char_array[i + cnt] = str(k)
          cnt += v
      print("".join(char_array))
  
  
  if __name__ == "__main__":
      main()
  
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"}]