#include<iostream>

 #include<cstring>

 #include<cstdio>

 #include<cmath>

 #include<algorithm>

 using namespace std;

 const long long N=;

 long long a[N],n,m,ans;

 long long gcd(long long x,long long y){

     if(y==)return x;

     else return gcd(y,x%y);

 }

 long long lcm(long long x,long long y){

     return x/gcd(x,y)*y;

 }

 void dfs(long long now,long long num,long long res,long long k){

     if(res==){

         if(num==)return;

         long long tmp=n/num;

         if(k&)ans+=tmp;

         else ans-=tmp;

         return;

     }

     if(now==m+)return ;

     if(lcm(num,a[now])<=n)dfs(now+,lcm(num,a[now]),res-,k);

     dfs(now+,num,res,k);

 }

 int main(){

     while(scanf("%lld%lld",&n,&m)!=EOF){

         n--;

         for(long long i=;i<=m;i++)scanf("%lld",&a[i]);

         for(long long i=;i<=m;i++)dfs(,,i,i);

         printf("%lld\n",ans);

     }

 }