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 PyPy3 (2.4.0) (judge verdict: Runtime Error)

from collections import defaultdict
length, types = map(int, input().split(" "))
match = [n for n in input().split(" ")]
cost = defaultdict(int)
cost.update({"1":2, "2":5, "3":5, "4":4, "5":5, "6":6, "7":3, "8":7, "9":6})

dp = ["" for n in range(length + 1)]

def compare_str(a, b):
    if len(a) == len(b):
        return a if a > b else b
    elif len(a) > len(b):
        return a
    return b
        

for m in match:
    dp[cost[m]] = m

for i in range(length):
    # print(dp, i)
    if dp[i]:
        for m in match:
            if i + cost[m] <= length:
                if dp[i + cost[m]]:
                    dp[i + cost[m]] = compare_str(dp[i + cost[m]], dp[i] + m)
                else:
                    dp[i + cost[m]] = dp[i] + m
print(dp[length])