prime_multiples

#include <bits/stdc++.h>
using namespace std;
#define ll long long
int main()
{
    ll n,k;
    cin>>n>>k;
    ll a[k+1];
    for (ll i=1; i<=k; i++) cin>>a[i];
    vector<pair<ll,ll>> v,res;
    v.push_back({a[1],-1});
    for (ll i=2; i<=k; i++){
        for (auto u:v){
            res.push_back({(u.first)*a[i],(u.second)*(-1)});
        }
        v.push_back({a[i],-1});
        for (auto u:res){
            v.push_back({u.first,u.second});
        }
        res.clear();
    }
    ll ans=0;
    for (auto u:v){
        ans=ans-(n/u.first)*(u.second);
    }
    cout<<ans;
}