#include <iostream>
#include <cstdio>
using namespace std;
typedef long long LL;
LL get[18];
LL gcd(LL m, LL n)
{
if(n == 0)
return m;
return gcd(n, m%n);
}
LL lcm(LL a, LL b)
{
LL t=gcd(a, b);
return a/t*b;
}
int main()
{
int n,m;
while(cin>>m>>n)
{
for(int i=0; i<n; i++)
cin>>get[i];
int sum=0;
for(int i=1; i<(1<<n); i++)
{
LL ans=1;
int cnt=0;
for(int j=0; j<n; j++)
{
if(i&(1<<j))
{
ans=lcm(ans,get[j]);
if(ans>m)
break;
cnt++;
}
}
if(ans>m)
continue;
if(cnt&1)
sum+=m/ans;
else
sum-=m/ans;
}
cout<<m-sum<<endl;
}
return 0;
}