#include <bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
//using namespace atcoder;
//using mint = modint1000000007;
//const int mod = 1000000007;
//using mint = modint998244353;
//const int mod = 998244353;
//const int INF = 1e9;
//const long long LINF = 1e18;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i,l,r)for(int i=(l);i<(r);++i)
#define rrep(i, n) for (int i = (n-1); i >= 0; --i)
#define rrep2(i,l,r)for(int i=(r-1);i>=(l);--i)
#define all(x) (x).begin(),(x).end()
#define allR(x) (x).rbegin(),(x).rend()
#define endl "\n"
#define P pair<int,int>
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
//約数列挙
vector<int> DivisorEnumeration(long long n) {
	vector<int> x;
	for (long long i = 1; i*i <= n; i++) {
		if (0 == n % i) {
			x.push_back(i);
			if (n != i * i) x.push_back(n / i);
		}
	}
	return x;
}
int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int n, m; cin >> n >> m;
	vector<int>open(n + 1);
	vector<int>cnt(n + 1);
	rep(i, m) {
		int a; cin >> a;
		open[a] = 1;
	}
	int ans = 0;
	rrep2(i, 1, n + 1) {
		auto v = DivisorEnumeration(i);
		if (1 != (abs(cnt[i] - open[i])) % 2) {
			ans++;
			continue;
		}
		for (auto e : v) {
			cnt[e]++;
		}
		/*
		cout << i << endl;
		rep(j, n + 1) {
			cout << cnt[j] << " ";
		}
		cout << endl;*/
	}
	cout << ans << endl;
	return 0;
}