#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll = long long;
using ld = long double;
using mint = modint998244353;

vector<ll> make_divisors(ll n) {
  vector<ll> res;
  for (ll i = 1; i * i <= n; i++) {
    if (n % i == 0) {
      res.push_back(i);
      if (i * i != n) res.push_back(n / i);
    }
  }
  sort(res.begin(), res.end());
  return res;
}

int main() {
  ll N, M; cin >> N >> M;
  vector<ll> A(M);
  for (auto &x: A) cin >> x;
  vector<vector<ll>> DIV {{}};
  vector<ll> ALL(N + 1, 0);
  vector<ll> DOOR(N + 1, 0);
  for (ll i = 1; i <= N; i++) {
    DIV.push_back(make_divisors(i));
    for (auto div: DIV[i]) {
      ALL[div] = (ALL[div] + 1) % 2;
    }
  }
  for (auto a: A) DOOR[a] = 1;
  ll cnt = 0;
  for (ll i = N; i >= 1; i--) {
    if (ALL[i] != DOOR[i]) {
      cnt++;
      for (auto div: DIV[i]) {
        DOOR[div] = (DOOR[div] + 1) % 2;
      }
    }
  }
  cout << cnt << endl;
  return 0;
}