#include<cstdio>

using namespace std;

#define LL long long

int a[];

int n,m;

int gcd(int x,int y) {

    if(y==)return x;

    else return gcd(y,x%y);

}

LL ans=;

void dfs(int num,int step,LL lcm) {

    if(lcm>n)return ;

    if(num==m+){

        if(step%==)ans-=n/lcm;//奇数个时加上

        else if(step)ans+=n/lcm;//偶数个时减去

        return ;

    }

    dfs(num+,step,lcm);

    LL tmp=lcm*a[num]/gcd(lcm,a[num]);//选择该数

    dfs(num+,step+,tmp);

}

int main () {

    scanf("%d%d",&n,&m);

    ans=n;

    for(int i=;i<=m;++i ) {

        scanf("%d",a+i);

    }

    dfs(,,);

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

    return ;

}