#include <fstream>
#include <algorithm>
using namespace std;
ifstream f("light2.in");
ofstream g("light2.out");
long long N,K;
long long D[25],x[25],cm=1,sol;
long long Power[25];
long long CMMDC(long long a,long long b)
{
    long long r=a%b;
    while(r!=0)
    {
        a=b;
        b=r;
        r=a%b;
    }
    return b;
}
void Back(long long k,long long cm)
{
    for(int i=x[k-1]+1;i<=K;i++)
    {
        x[k]=i;
        long long aux=cm;
        cm=(cm*D[x[k]])/CMMDC(cm,D[x[k]]);
        if(cm>N)
        {
            cm=aux;
            continue;
        }

        if(k%2==0)
        {
            sol-=(N/cm)*Power[k-1];
        }
        else
            sol+=(N/cm)*Power[k-1];
        if(k<K)
            Back(k+1,cm);
        cm=aux;
    }
}
void Read()
{
    f>>N>>K;
    for(int i=1;i<=K;i++)
        f>>D[i];
    sort(D+1,D+K+1);
}
int main()
{
    Read();
    Power[0]=1;
    for(int i=1;i<=K;i++)
        Power[i]=Power[i-1]*2;
    Back(1,1);

    g<<sol<<'\n';
    return 0;
}