#include<iostream.h> 
#include<fstream.h> 
long long n,a[100]; 
long long viz[200000000]; 
int main() 
{long long z=0,i,j,k; 
ifstream f("light2.in"); 
ofstream h("light2.out"); 
f>>n; 
f>>k; 
for(i=1;i<=k;i++) 
f>>a[i]; 
for(i=2;i<=n;i++) 
for(j=1;j<=k;j++) 
if(i%a[j]==0&&viz[i]%2==0) 
{z++; 
viz[i]=viz[i]+1;} 
else
if(i%a[j]==0&&viz[i]%2!=0) 
{z--; 
viz[i]=viz[i]+1;} 
h<<z; 
return 0;}