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 Java8 (OpenJDK 1.8.0) (judge verdict: Runtime Error)

import java.util.*;
public class Main{
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		int a = scan.nextInt();
		int b = scan.nextInt();
		int[] e = new int[b];
		int[] f = new int[b];
		int[] ans = new int[b];
		int[] n = {2,5,5,4,5,6,3,7,6};
		for(int i=0;i<b;i++){
			int c =scan.nextInt();
			e[i] =c;
			f[i] =n[c-1];
		}
		Arrays.sort(f);
		Arrays.sort(e);
		int p=0;
		int u = a/f[0];
		ans[0]=u;
		int k = a%f[0];
		boolean flg=true;
		while(flg){
			if(k==0){break;}
			a=k+f[0];
			ans[0]--;
			for(int i=p;i<b;i++){
				if(a%f[i]==0){
					ans[i]++;
					flg=false;
					break;
				}
			}
			if(flg){
				while(true){
					if(a-f[p]>0){
						a-=f[p];
						ans[p]++;
					}else{
						break;
					}
				}
			}
			k=a;
			p++;
		}

		for(int i=b;i>0;i--){
			for(int l=8;l>=0;l--){
				if(n[l]==f[i-1]){
					for(int w=0;w<b;w++){
						if(l+1==e[w]){
							for(int y=0;y<ans[i-1];y++){
								System.out.print(f[i-1]);
							}
						}
					}
				}
			}
		}

	}
}