1 #include <cstdio>
 2 #include <iostream>
 3 #include <algorithm>
 4 using namespace std;
 5 int i,n,m,k[12];
 6 long long d,x,y,ans;
 7 void exgcd(long long a,long long b,long long &d,long long &x,long long &y)
 8 {
 9     if (!b) d=a,x=1,y=0; 
10     else exgcd(b,a%b,d,y,x),y=y-x*(a/b);
11 }
12 long long gcd(long long x,long long y) { return y?gcd(y,x%y):x; }
13 long long lcm(long long x,long long y) { return x*y/gcd(x,y); }
14 void dfs(int t,long long tot1,long long tot2,long long x1,long long x2,long long w)
15 {
16     if (x1>n||x2>n) return;
17     if (t>m)
18     {
19         if (tot1==0||tot2==0) return;
20         exgcd(x1,x2,d,x,y);
21         if (d<0) x=-x,y=-y,d=-d; 
22         if (d>1) return;
23         x=(x%x2+x2)%x2;
24         ans+=w*((1LL*n/x1-x)/x2+(x1*x<=n));
25         return;
26     }
27     dfs(t+1,tot1,tot2,x1,x2,w);
28     dfs(t+1,tot1+1,tot2,lcm(x1,k[t]),x2,-w);
29     dfs(t+1,tot1,tot2+1,x1,lcm(x2,k[t]),-w);
30 }
31 int main()
32 {
33     freopen("sazetak.in","r",stdin);
34     freopen("sazetak.out","w",stdout);
35     scanf("%d%d",&n,&m);
36     for (int i=1;i<=m;i++) scanf("%d",&k[i]);
37     k[++m]=n;
38     dfs(1,0,0,1,1,1);
39     printf("%lld",ans);
40     return 0;
41 }