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: Wrong Answer)

D = [0,2,5,5,4,5,6,3,7,6]
N,M,*A = $<.read.split.map(&:to_i)
A.sort_by!{|d| (D[d]<<4) + (9-d) }

n,a,popped = N,[],false
until n == 0
	if ! popped and d = A.find{|d| D[d] <= n }
		a << d
		n -= D[d]
		popped = false
	else
		n += D[a[-1]]
		if d = A[A.index(a[-1])+1,A.size].find{|d| D[d] <= n }
			a[-1] = d
			n -= D[d]
			popped = false
		else
			a.pop
			popped = true
		end
	end
end

puts a.sort.reverse.join('')