using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var c = NList;
        var (n, m) = (c[0], c[1]);
        var a = new int[0];
        if (m == 0) ReadLine();
        else a = NList;
        var dp = new bool[n + 1];
        foreach (var ai in a) dp[ai] = true;
        var ans = 0;
        for (var i = n; i > 0; --i)
        {
            if (dp[i])
            {
                foreach (var p in PList(i)) dp[p] = !dp[p];
            }
            else ++ans;
        }
        WriteLine(ans);
    }
    static List<int> PList(int n)
    {
        var ans = new List<int>();
        for (var i = 1; i * i <= n; ++i)
        {
            if (n % i == 0)
            {
                ans.Add(i);
                if (i * i < n) ans.Add(n / i);
            }
        }
        return ans;
    }
}