import java.util.*;
import java.io.*;
public class Q4 {
	protected static int total[];
	protected static int coins[];
	public static void main(String args[]) throws IOException
	{
		PrintWriter pw=new PrintWriter(new FileWriter("OUT4.txt"));
		Scanner sc=new Scanner(new FileReader("DATA4.txt"));

		for(int i=0;i<5;i++)
		{
			int amount=sc.nextInt();
			total=new int[amount+1];
			Arrays.fill(total, 99999);
			total[0]=0;
			int n=sc.nextInt();
			coins=new int[n];
			
			for(int j=0;j<n;j++)
			{
				coins[j]=sc.nextInt();
			}
			
			Arrays.sort(coins);
			find(amount);
			
			if(total[amount]>=99999)
			{
				System.out.println(0);
			}
			else
				pw.println(total[amount]);
		}

		pw.close();
		System.exit(0);
		
	}
	
	public static void find(int amount)
	{
		for(int j=1;j<=amount;j++)
		{
			int min=99999;
			for(int i=0;i<coins.length;i++)
			{
				

				if(j>=coins[i])
				{
					int count=total[j-coins[i]]+1;
					if(min>count)
					{
						min=count;
					}
				}
			//	else
				//{
				//	break;
				//}
			
			}
			total[j]=Math.min(total[j], min);
		}
		
	}
}