#include<fstream>
#define dmax 30
using namespace std;

long long n,k;
int d[dmax];
long long sol;


void citire()
{
 int i;
	
 ifstream fin("light2.in");
 
 fin>>n>>k;
 for (i=1; i<=k; i++)
	 fin>>d[i];
 
 fin.close();
}


void solve()
{
 long long i,j,a;
	
 for (i=1; i<=n; i++)
	 {
	  a = 0;
	  for (j=1; j<=k; j++)
		  if (i % d[j] == 0)
			  a++;
	 
	  if (a % 2 == 1)
		  sol++;
	 }
}


void afisare()
{
 ofstream fout("light2.out");
 
 fout<<sol;
 
 fout.close();
}


int main()
{
	
 citire();
 solve();
 afisare();
	
 return 0;
}