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: Wrong Answer)

n, m = map(int, input().split())
a = list(map(int, input().split()))
c = [0, 2, 5, 5, 4, 5, 6, 3, 7, 6]  # マッチ棒の本数との変換
f = [0] + [0] * 10000  # DP

# マッチ棒の本数分だけ回す
for i in range(n):
    # 入力の1番目(k)は不必要
    i += 1
    for x in a:
        # 数字が大きいほうが良いから全探索
        # ソートしても出来るけれど作るの面倒

        o = c[x]  # マッチ棒の本数に変換

        if i - o >= 0:  # マッチ棒の上限を超えないように判定
            # マッチ棒の本数分だけ減らして桁を繰り上げて足す
            f[i] = max(f[i], f[i - o] * 10 + x)

print(f[n])