#include <bits/stdc++.h>
#pragma comment(linker, "/STACK:10000000")
const long double LDINF = 9128739847123.00;
const long double eps = 1e-9;
const int INF = 1 << 30;
const long double pi = fabsl(atan2(0.0, -1.0));
using namespace std;
long long n;
int k;
int a[1110];
void Load() {
  cin >> n >> k;
  for (int i = 0; i < k; i++) {
    cin >> a[i];
  }
  sort(a, a + k);
  reverse(a, a + k);
}
const int MAXN = 100000;
long long dp[MAXN][101];
long long go(long long m, int i) {
  if (m == 0) return 0;
  if (i == k) return m;
  if (m < MAXN && dp[m][i] != -1) return dp[m][i];
  if (m < MAXN) dp[m][i] = 0;
  long long res = 0;
  res = go(m, i + 1) - go(m / a[i], i + 1);
  if (m < MAXN) dp[m][i] = res;
  return res;
}
void Solve() {
  memset(dp, -1, sizeof dp);
  cout << go(n, 0);
}
int main() {
  Load();
  Solve();
  return 0;
}
