#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (int)(n); i++)

using namespace std;
using LL = long long;
using P = pair<int,int>;
using vv = vector<vector<int>>;
const int INF = (int)1e9;
const LL LINF = (LL)1e18;
const int Max_N = (int)2e5;

int main(){
	int N, M;
	cin >> N >> M;
	assert(1 <= N && N <= Max_N);
	assert(0 <= M && M <= N);
	vector<int> A(M), B(N+1);
	rep(i,M) cin >> A[i];
	rep(i,M) assert(1 <= A[i] && A[i] <= N);
	rep(i,M-1) assert(A[i] < A[i+1]);
	rep(i,M) B[A[i]] = 1;
	vector<int> L(N+1);
	int ans = 0;
	for(int i = N; i > 0; i--){
		if(L[i] == B[i]) ans++;
		else{
			for(int j = 1; j * j <= i ; j++){
				if(i % j == 0){
					L[j] ^= 1;
					if(j * j != i) L[i/j] ^= 1;
				}
			}
		}
	}
	cout << ans << endl;

	return 0;
}