#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pll = pair<ll, ll>;
#define drep(i, cc, n) for (ll i = (cc); i <= (n); ++i)
#define rep(i, n) drep(i, 0, n - 1)
#define all(a) (a).begin(), (a).end()
#define pb push_back
#define fi first
#define se second

const ll MOD = 1000000007;
const ll MOD2 = 998244353;
const ll INF = 1LL << 60;
const ll N_MAX = 2e5;

int main(){
    ll n, m;
    cin >> n >> m;

    vector<bool> isOpen(n+1, false);
    rep(i, m){
        ll a;
        cin >> a;
        isOpen[a] = true;
    }

    vector<vector<ll>> mul(n+1);
    for(ll i=1; i<=n; i++){
        for(ll j=i; j<=n; j+=i){
            mul[j].pb(i);
        }
    }

    ll ans = 0;
    vector<ll> cnt(n+1, 0);
    for(ll i=n; i>=1; i--){
        if(cnt[i]%2 == isOpen[i]){
            ans++;
        }else{
            for(ll j : mul[i]){
                cnt[j]++;
            }
        }
    }

    cout << ans << endl;
}