using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace kadai
{
    class Program
    {
        static void Main(string[] args)
        {
            int L = int.Parse(Console.ReadLine());
            int N = int.Parse(Console.ReadLine());
            int[] W = Console.ReadLine().Trim().Split(' ').Select(x => int.Parse(x)).ToArray();
            Array.Sort(W);

            int sum = 0;
            int count = 0;

            for (int i = 0; i < N; i++)
            {

                sum += W[i];
                //一回目のループ　sum -> W[0]
                //二回目のループ　sum -> W[0] + W[1]
                //二回目のループ　sum -> W[0] + W[1]+W[2]
                if (5 < sum)
                {
                    break;
                }

                count++;
            
            }
            
            Console.WriteLine(count);

        }
    }
}