#include<cstdio>
#define L 19000000
using namespace std;

void citeste();
void rezolva();
void afiseaza();

char f[L];
unsigned long long s=0,n;
int k,x;
 
 void citeste()
 {
    
    freopen("light2.in","r",stdin);
    
    scanf("%lld %d",&n,&k);
    
  int i;
    
    for(i=1;i<=k;i++)
    {
        scanf("%d",&x);
        rezolva();
	}
    fclose(stdin);
 }
 
 
 void rezolva()
 {
    unsigned long long i;
	
	 for(i=x;i<=n;i+=x) 
	 {
		 if(f[i]) f[i]=0;
		 else f[i]=1;
	 }
 }
 
 

void sum()
{
	unsigned long long i;
	
    for(i=1;i<=n;i++) if(f[i]) s++;
}



void afiseaza()
{
    freopen("light2.out","w",stdout);
    
    printf("%lld\n",s);
    
    fclose(stdout);
}




int main()
{
    citeste();
    sum();
    afiseaza();
    
    return 0;
}