#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;

#define rep(i, n) for(ll i = 0; i < n; i++)
#define rep2(i, m, n) for(ll i = m; i <= n; i++)
#define rrep(i, m, n) for(ll i = m; i >= n; i--)
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define MAX(x) *max_element(all(x))
#define MIN(x) *min_element(all(x))
#define SZ(a) ((ll)(a).size())
#define bit(n, k) ((n >> k) & 1)
using namespace std;
using ll = long long;
using P = pair<ll, ll>;
const int dx[4] = { -1, 1, 0, 0 };
const int dy[4] = { 0, 0, 1, -1 };
const int inf = 1e9 + 1;
const ll INF = 1e18;
const double pi = acos(-1);

using Graph = vector<vector<ll>>;
using REV_PQ = priority_queue<ll, vector<ll>, greater<ll>>;
using PQ = priority_queue<ll>;

//typedef atcoder::modint998244353 mint;
//typedef atcoder::modint1000000007 mint;

const int SIZE = 200010;
ll powll(ll n, ll x) {
    // return n ^ x;

    ll ret = 1;
    rep(i, x) ret *= n;

    return ret;
}

/*struct Edge { ll u, v, cost; };

bool comp(const Edge& e1, const Edge& e2) {
    return e1.cost < e2.cost;
}*/


void OutputYesNo(bool val) {

    if (val) cout << "Yes" << endl;
    else cout << "No" << endl;
}
void OutputTakahashiAoki(bool val) {

    if (val) cout << "Takahashi" << endl;
    else cout << "Aoki" << endl;
}

void OutPutInteger(ll x) { cout << x << endl; }
void OutPutString(string x) { cout << x << endl; }
/*

int t; cin >> t;
rep2(i, 1, t){
    cout << "Case #" << i << ":" << endl;
    cout << "Case #" << x << ":" << " ";
}
*/

int sc[SIZE];
int Count[SIZE];
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int n, m; cin >> n >> m;
    vector<int> a(m);
    rep(i, m) cin >> a[i];
    rep(i, m) sc[a[i]] = 1;

    int res = 0;
    rrep(x, n, 1) {
        for (int i = 1; i * i <= x; i++) {
            if (x % i == 0) {
                Count[i]++;
                if (i * i != x) Count[x / i]++;
            }
        }
        if ((Count[x] + sc[x]) % 2 == 1) {
            res++;
            for (int i = 1; i * i <= x; i++) {
                if (x % i == 0) {
                    Count[i]--;
                    if (i * i != x) Count[x / i]--;
                }
            }
        }
    }

    OutPutInteger(res);
}