/* -*- coding: utf-8 -*-
 *
 * 1946.cc:  No.1946 ロッカーの問題 - yukicoder
 */

#include<cstdio>
#include<algorithm>
 
using namespace std;

/* constant */

const int MAX_N = 200000;

/* typedef */

/* global variables */

int rs[MAX_N + 1];

/* subroutines */

/* main */

int main() {
  int n, m;
  scanf("%d%d", &n, &m);

  for (int i = 0; i < m; i++) {
    int ai;
    scanf("%d", &ai);
    rs[ai] = 1;
  }

  int c = 0;
  for (int i = n; i >= 1; i--) {
    if (rs[i]) {
      for (int p = 1; p * p <= i; p++)
	if (i % p == 0) {
	  int q = i / p;
	  rs[p] ^= 1;
	  if (q != p) rs[q] ^= 1;
	}
    }
    else
      c++;
  }

  printf("%d\n", c);
  return 0;
}