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 PyPy2 (5.6.0) (judge verdict: Accepted)

T=[(1,2),(2,5),(3,5),(4,4),(5,5),(6,6),(7,3),(8,7),(9,6)]
 
N,M=map(int, raw_input().split())
A=map(int, raw_input().split())
 
 
P=[]
for i in A:
	P.append(T[i-1])
 
 
dp=[ None for i in range(N+1) ]
dp[0]=""
 
 
for i in range(N):
	#print "i :::: ",i,dp
	if dp[i] is not None:
		for num, match in P:
			if i+match<=N:
 
				if dp[i+match] is None:
					dp[i+match]=dp[i]+str(num)
				else:
					l1=len(dp[i+match])
					l2=len(dp[i]+str(num))
					if l1>l2:
						pass
					elif l1<l2:
						dp[i+match]=dp[i]+str(num)
					else:
						dp[i+match]=max( dp[i+match] , dp[i]+str(num) )
 
 
print dp[N]