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 PHP7 (7.0.15) (judge verdict: Wrong Answer)

<?php
$m=explode(' ',trim(fgets(STDIN)));
$limit=$m[0];
$nums=explode(' ',trim(fgets(STDIN)));
$_use = [2,5,5,4,5,6,3,7,6];
foreach($nums as $v){
  $array[]=[$v,$_use[$v-1]];
}
usort($array,function($a,$b){return $a[1]-$b[1];});
$item = array_fill(0, $limit + 1, 0);
$value = array_fill(0, $limit + 1, 0);
$_l = $limit;
$b=[];
$lazy=0;
for($pt=$lazy;$pt<sizeof($array);$pt++){
  if($_l%$array[$pt][1] == 0){
    $b[]=$array[$pt][0];
    $_l=0;
    break;
  }else{
    $_l -= $array[$pt+1][1];
    $b[]=$array[$pt+1][0];
    $pt=0;
  }
  if($pt==sizeof($array)-1){
    $b=[];$pt=0;$lazy++;$_l=$limit;
  }
}
rsort($b);
echo implode("",$b);