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 Python (3.4.3) (judge verdict: Runtime Error)

from operator import itemgetter
tik = [[1,2],[7,3],[4,4],[5,5],[3,5],[2,5],[9,6],[8,7],[6,6]]
dic = {"1":2,"7":3,"4":4,"5":5,"3":5,"2":5,"9":6,"8":7,"6":6}

n,k = map(int, input().split())
x = list(map(int, input().split()))
inf = float("INF")
dp = [0]+[-1]*(n+10)
q = []
for i in range(k):
    q.append([x[i],dic[str(x[i])]])

q = sorted(q, key=itemgetter(1), reverse=False)

s = []
p=0
t = 0
for i in range(n):
    for j in range(k):
        if i+q[j][1] <=n+10000000:
            if dp[i]!=-1:
            
                if  dp[i]==0:
                    dp[i+q[j][1]] = q[j][0]
                else:dp[i+q[j][1]] = str(dp[i])+str(q[j][0])
        #if i+q[j][1] ==n:
            #print(dp[20])
s = list(dp[n])
s.sort()
s = s[::-1]
print(''.join(s))