#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
using ll=long long;
using Graph=vector<vector<int>>;
#define MAX 3000
//#define MOD 1000000007
#define MOD 998244353
#define INF 1000000000
//#define INF 1000000000000000000

int main(){
  int N,M;
  cin>>N>>M;
  vector<int> A(M);
  vector<int> wrong(N+1,0);
  for(int i=0;i<M;i++){
    cin>>A[i];
    wrong[A[i]]=1;
  }

  vector<int> open(N+1,0);
  for(int i=1;i<=N;i++){
    vector<int> divd;
    for(int j=1;j*j<=i;j++){
      if(i%j==0){
        divd.push_back(j);
        divd.push_back(i/j);
      }
    }
    sort(divd.begin(),divd.end());
    divd.erase(unique(divd.begin(),divd.end()),divd.end());

    for(int d:divd){
      open[d]=1-open[d];
    }
  }

  vector<int> ans;
  for(int i=N;i>0;i--){
    if(wrong[i]!=open[i]){
      ans.push_back(i);
      vector<int> divd;
      for(int j=1;j*j<=i;j++){
        if(i%j==0){
          divd.push_back(j);
          divd.push_back(i/j);
        }
      }
      sort(divd.begin(),divd.end());
      divd.erase(unique(divd.begin(),divd.end()),divd.end());

      for(int d:divd){
        wrong[d]=1-wrong[d];
      }
    }
  }

  cout<<ans.size()<<'\n';
}