#include <bits/stdc++.h>
using namespace std;
#define int long long
signed main(){
  int N,M;
  cin>>N>>M;
  vector<int> A(N,0);
  for(int i=1;i<=N;i++){
    int now = i;
    while(now <= N){
      A[now-1] = 1-A[now-1];
      now += i;
    }
  }
  vector<int> S(N,0);
  for(int i=0;i<M;i++){
    int a;
    cin>>a;
    S[a-1] = 1;
  }
  int ans = 0;
  for(int i=1;i<=N;i++){
    if(A[i-1] != S[i-1]){
      ans++;
      int now = i;
      while(now <= N){
        A[now-1] = 1-A[now-1];
        now += i;
      }
    }
  }
  cout<<ans<<endl;
}