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 Pascal (FPC 2.6.2) (judge verdict: Accepted)

const
	num:array[1..9] of longint=(2,5,5,4,5,6,3,7,6);
var
	a:array[-10..10] of longint;
	f:array[-1110..10010] of longint;
	i,j,n,m,t:longint;
begin
	readln(n,m);
	for i:=1 to m do read(a[i]);
	for i:=1 to m-1 do
		for j:=1 to m-i do
			if a[j]<a[j+1] then
			begin
				t:=a[j]; a[j]:=a[j+1]; a[j+1]:=t;
			end;
	for i:=-10 to n do f[i]:=-1000000000;
	f[0]:=0;
	for i:=1 to m do
		for j:=num[a[i]] to n do
			if f[j-num[a[i]]]+1>f[j] then
				f[j]:=f[j-num[a[i]]]+1;
	for i:=1 to m do
		while (f[n-num[a[i]]]+1=f[n]) and (n>=num[a[i]]) do
		begin
			n:=n-num[a[i]];
			write(a[i]);
		end;
	writeln;
end.