// yukicoder/1946/main.cpp
// author: @___Johniel
// github: https://github.com/johniel/

#include <bits/stdc++.h>

#define each(i, c) for (auto& i : c)
#define unless(cond) if (!(cond))
// #define endl "\n"

using namespace std;

template<typename P, typename Q> ostream& operator << (ostream& os, pair<P, Q> p) { os << "(" << p.first << "," << p.second << ")"; return os; }
template<typename P, typename Q> istream& operator >> (istream& is, pair<P, Q>& p) { is >> p.first >> p.second; return is; }
template<typename T> ostream& operator << (ostream& os, vector<T> v) { os << "("; for (auto& i: v) os << i << ","; os << ")"; return os; }
template<typename T> istream& operator >> (istream& is, vector<T>& v) { for (auto& i: v) is >> i; return is; }
template<typename T> ostream& operator << (ostream& os, set<T> s) { os << "#{"; for (auto& i: s) os << i << ","; os << "}"; return os; }
template<typename K, typename V> ostream& operator << (ostream& os, map<K, V> m) { os << "{"; for (auto& i: m) os << i << ","; os << "}"; return os; }

template<typename T> inline T setmax(T& a, T b) { return a = std::max(a, b); }
template<typename T> inline T setmin(T& a, T b) { return a = std::min(a, b); }

using lli = long long int;
using ull = unsigned long long;
using point = complex<double>;
using str = string;
template<typename T> using vec = vector<T>;

constexpr array<int, 8> di({0, 1, -1, 0, 1, -1, 1, -1});
constexpr array<int, 8> dj({1, 0, 0, -1, 1, -1, -1, 1});
constexpr lli mod = 1e9 + 7;
// constexpr lli mod = 998244353;

int main(int argc, char *argv[])
{
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.setf(ios_base::fixed);
  cout.precision(15);

  int n, m;
  while (cin >> n >> m) {
    vec<int> a(m);
    cin >> a;

    const int N = 2 * 1e5 + 3;
    static bool ex[N];
    fill(ex, ex + N, true);
    each (i, a) ex[i] = false;

    static bool vis[N];
    fill(vis, vis + N, true);
    for (lli i = n; 0 < i; --i) {
      for (lli j = 1; j * j <= i; ++j) {
        if (i % j == 0) {
          lli k = i / j;
          vis[j] = !vis[j];
          if (j != k) vis[k] = !vis[k];
        }
      }
    }
    int z = 0;
    for (lli i = n; 0 < i; --i) {
      if (ex[i] != vis[i]) {
        ++z;
        for (lli j = 1; j * j <= i; ++j) {
          if (i % j == 0) {
            lli k = i / j;
            vis[j] = !vis[j];
            if (j != k) vis[k] = !vis[k];
          }
        }
      }
    }
    cout << z << endl;
  }

  return 0;
}