#include<stdio.h>
#include<vector>
#define NR 135000000
using namespace std;
long long K,N,d,cont,i,j;
FILE *in,*out;

inline long long min(long long a,long long b)
{
    if(a>b)
        return b;
    return a;
}

vector<bool> viz(NR);

int main()
{
    in=fopen("light2.in","rt");
    out=fopen("light2.out","wt");
    fscanf(in,"%lld",&N);


    fscanf(in,"%lld",&K);
    for(i=1;i<=K;i++)
    {
        fscanf(in,"%lld",&d);
        for(j=d;j<=N;j+=d)
        {
            if(!viz[j])
            {
                viz[j]=true;
                cont++;
            }
            else
            {
                viz[j]=false;
                cont--;
            }
        }
    }
    fprintf(out,"%lld",cont);

    return 0;
}