#include <iostream>
#include <cstdint>
#include <vector>

using namespace std;

int main()
{
	cin.tie(nullptr);
	ios::sync_with_stdio(false);

	uint32_t N, M, i, j;
	cin >> N >> M;
	vector<uint32_t> A(M);
	for (i = 0; i != M; ++i) cin >> A[i];

	vector<bool> result(N, false);
	for (i = 0; i != M; ++i) result[A[i] - 1] = true;

	vector<bool> is_skipped(N, false);
	uint32_t ans = 0;
	for (i = N; i != 0; --i)
	{
		uint32_t skip_count = 0;
		for (j = i * 2; j <= N; j += i)
			if (is_skipped[j - 1]) ++skip_count;

		if (((N / i - skip_count) & 1) != result[i - 1])
			is_skipped[i - 1] = true, ++ans;
	}

	cout << ans << '\n';
	return 0;
}