#include<iostream>
#include<cstdio>
using namespace std;
int n,m,ans=0;
int a[21];
int main()
{//freopen("count.in","r",stdin);
 //freopen("count.out","w",stdout);
 cin>>n>>m; 
 ans=n;
 for(int i=1;i<=m;i++)
 cin>>a[i];
 for(int i=1;i<=n;i++)
 for(int j=1;j<=m;j++)
  {if(a[j]>n)break;
   if(i%a[j]==0)
   {ans--;break;
   }
  }
  cout<<ans;
  return 0;
}