#include<algorithm>
using namespace std;

#define DIM 25

long long a[DIM],n,sol;
int b[DIM],k;

inline long long cmmmc (long long nr1,long long nr2)
{
    long long aux2=nr2,aux;
    while(nr2)
    {
        aux=nr1%nr2;
        nr1=nr2;
        nr2=aux;
    }
    return (long long)aux2/nr1;
}

inline int smn (int x)
{
    if(x%2==1)
        return 1;
    return -1;
}

void back (int x,int poz,long long  rez)
{
    if(x==k+1)
        return ;
    else
    {
        int i;
        long long aux;
        for(i=poz;i<=k;++i)
        {
            b[x]=i;

            if(x!=1)
                aux=(long long)rez*cmmmc(rez,a[i]);
            else
                aux=(long long)rez*a[i];

            sol+=(long long)smn(x)*(n/aux)*(1<<(x-1));
            back(x+1,i+1,aux);
        }
    }
}

int main ()
{
    freopen("light2.in","r",stdin);
    freopen("light2.out","w",stdout);
    int i;

    scanf("%lld\n%d\n",&n,&k);
    for(i=1;i<=k;++i)
        scanf("%lld",&a[i]);
    back(1,1,1);

    printf("%lld\n",sol);
    return 0;
}