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: Time Limit Exceeded)

N , M = map(int,input().split())
L = sorted(list(map(int,input().split())))
table =  [0,2,5,5,4,5,6,3,7,6]
L_val =sorted( list(map(lambda x:(table[x],x),L)))
number = ["0" for i in range(10**4+10)]

def comp(x,y):
    if len(x) >len(y):
        return 0
    elif len(x) < len(y):
        return 1
    else:
        for i in range(len(x)):
            if x[i] == y[i]:
                i+=1
            elif int(x[i]) < int(y[i]):
                return 1
            elif int(x[i]) > int(y[i]):
                return 0
        return 0



for x in L_val:
    number[x[0]] = str(x[1])

for i in range(10**4):
    tmp = number[i]
    if tmp=="0":
        continue
    for x in L_val:
        if  comp(number[i+x[0]],tmp + str(x[1])):
            number[i+x[0]] = tmp + str(x[1])

print(number[N])