Problem:
Score : 400 points

Problem 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.

Constraints

All values in input are integers.

2 \leq N \leq 10^4

1 \leq M \leq 9

1 \leq A_i \leq 9

A_i are all different.

There exists an integer that can be formed by exactly N matchsticks under the conditions.

Input

Input is given from Standard Input in the following format:

N M
A_1 A_2 ... A_M

Output

Print the largest integer that can be formed with exactly N matchsticks under the conditions in the problem statement.

Sample Input 1

20 4
3 7 8 4

Sample Output 1

777773

The integer 777773 can be formed with 3 + 3 + 3 + 3 + 3 + 5 = 20 matchsticks, and this is the largest integer that can be formed by 20 matchsticks under the conditions.

Sample Input 2

101 9
9 8 7 6 5 4 3 2 1

Sample Output 2

71111111111111111111111111111111111111111111111111

The output may not fit into a 64-bit integer type.

Sample Input 3

15 3
5 4 6

Sample Output 3

654

Solution in Ruby (2.3.3) (judge verdict: Time Limit Exceeded)

# https://atcoder.jp/contests/abc118/tasks/abc118_d
=begin
20 4
3 7 8 4
777773

101 9
9 8 7 6 5 4 3 2 1
71111111111111111111111111111111111111111111111111

15 3
5 4 6
654
=end
N, _M = gets.split.map(&:to_i)
valid_nums = gets.split
MATCH_NUM = {
  '1' => 2,
  '2' => 5,
  '3' => 5,
  '4' => 4,
  '5' => 5,
  '6' => 6,
  '7' => 3,
  '8' => 7,
  '9' => 6
}.freeze

dp = ['']

1.step(N) do |i|
  valid_nums.each do |str|
    next if i < MATCH_NUM[str] || !dp[i - MATCH_NUM[str]]
    dp[i] = [(dp[i - MATCH_NUM[str]].to_s + str).to_i, dp[i].to_i].max
  end
end

p dp[N]