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: d=[0,2,5,5,4,5,6,3,7,6]
  N,M=map(int,input().split())
  A=list(map(int,input().split()))
  l=[]
  for a in A:
      l.append([a,d[a]])
  l.sort(key=lambda x:x[0],reverse=True)
  l.sort(key=lambda x:x[1])
  min_val,min_match=l[0]
  
  ans=[]
  if N%min_match==0:
      ans.append(int(str(min_val)*(N//min_match)))
  from itertools import combinations_with_replacement
  for i in range(1,M):
      f = False
      r = 1
      while not f:
          for p in combinations_with_replacement(l[1:],r):
          v=[]
          m_sum=0
          for val,mat in p:
              v.append(str(val))
              m_sum+=mat
          if (N-m_sum)%min_match==0:
              ans.append(int(''.join(sorted(v+
                  [str(min_val)]*((N-m_sum)//min_match),reverse=True))))
          f = (len(ans) == 0)
          r += 1
  print(max(ans))
  
  
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"}]