#include <fstream>
using namespace std;
ifstream fin("light2.in");
ofstream fout("light2.out");

#define ll long long

ll i,j,N,K,R;
ll d[25];

void citire()
{
	fin >> N;
	fin >> K;
	for(i=1;i<=K;i++)
		fin >> d[i];
}

ll cmmdc(ll a, ll b)
{
	ll r;
	while(b>0)
	{
		r=a%b;
		a=b;
		b=r;
	}
	return a;
}
ll cmmmc(ll a, ll b)
{
	ll r=1LL*a*b/cmmdc(a,b);
	return r;
}

void back(int poz, int nrf, ll P)
{
	ll CMMMC;
	if(poz==K+1 || P>N)
		return;
	CMMMC=cmmmc(P,d[poz]);
	if(nrf&1)
		R+=(1LL*(N/CMMMC)*(1<<(nrf-1)));
	else
		R-=(1LL*(N/CMMMC)*(1<<(nrf-1)));
	back(poz+1,nrf,P);
	back(poz+1,nrf+1,CMMMC);
}

int main()
{
	citire();
	back(1,1,1);
	fout << R;
}