#include <iostream>
#include <fstream>
#include <cmath>
#include <algorithm>

using namespace std;

ifstream f ("light2.in");
ofstream g ("light2.out");
int n,k,i,j,t;
int vek[1000000];
int cek[1000000];
int main()
{
    f>>n;
    f>>k;
    int siz=0;
    int p=1;
    for(i=1;i<=k;++i)
    {
        f>>t;
        p=-1;
        for(j=siz;j>=1;j--)
        {
            int c=t*vek[j]/__gcd(t,vek[j]) *vek[j]/abs(vek[j]);
            vek[siz+j]=p*c;
            cek[siz+j]=cek[j]+1;

        }
        siz*=2;
        siz++;
        vek[siz]=t;
        cek[siz]=1;

    }
    int s=0;
    for(int i=1;i<=siz;++i)
    {
                   // cout<<vek[i]<<" c:"<<cek[i]<<"\n";

      s+=cek[i]*n/vek[i];
    }
    g<<s;
    return 0;
}