#include <bits/stdc++.h>
using namespace std;
void debug_out() { cerr << endl; }
template<class T> ostream& prnt(ostream& out, T v) { out << v.size() << '\n'; for(auto e : v) out << e << ' '; return out;}
template<class T> ostream& operator<<(ostream& out, vector <T> v) { return prnt(out, v); }
template<class T> ostream& operator<<(ostream& out, set <T> v) { return prnt(out, v); }
template<class T1, class T2> ostream& operator<<(ostream& out, map <T1, T2> v) { return prnt(out, v); }
template<class T1, class T2> ostream& operator<<(ostream& out, pair<T1, T2> p) { return out << '(' << p.st << ' ' << p.nd << ')'; }
template <typename Head, typename... Tail> void debug_out(Head H, Tail... T) { cerr << " " << H; debug_out(T...);}
#define dbg(...) cerr << #__VA_ARGS__ << " ->", debug_out(__VA_ARGS__)
#define dbg_v(x, n) do{cerr<<#x"[]: ";for(int _=0;_<n;++_)cerr<<x[_]<<" ";cerr<<'\n';}while(0)
#define dbg_ok cerr<<"OK!\n"
#define ll long long
#define ld long double
#define ull unsigned long long
#define pii pair<int,int>
#define MOD 1000000007
#define zeros(x) x&(x-1)^x
#define fi first
#define se second
#define Nmax 500005
const long double PI = acos(-1);

ll n,k,v[25];

int main(){
	freopen("light2.in","r",stdin);
	freopen("light2.out","w",stdout);
    ios::sync_with_stdio(false);
    cin >> n >> k;
    for (int i=1;i<=k;i++) cin >> v[i];

    int mx = 1<<k;
	ll ans = 0, mm, d, cnt;
    for (int i=1;i<mx;i++){
    	d = 0; mm = 1; cnt = 0;
    	for (int j=0;j<k;j++){
    		if (i & (1<<j)){
    			d = __gcd(d, v[j+1]);
    			mm *= v[j+1];
    			cnt++;
    		}
    	}
    	if (cnt > 1) mm /= d;
    	ans += cnt * (n / mm) * (cnt % 2 ? 1 : -1);
    }

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