#include <bits/stdc++.h>
using namespace std;
const long double eps = 1e-9;
const int inf = (1 << 30) - 1;
const long long inf64 = ((long long)1 << 62) - 1;
const long double pi = acos(-1);
template <class T>
T sqr(T x) {
  return x * x;
}
template <class T>
T abs(T x) {
  return x < 0 ? -x : x;
}
const int MAXK = 105;
const int magic = 100 * 1000;
int a[MAXK];
int ans_small[MAXK][magic];
long long get_ans(long long n, int k) {
  if (k == 0) {
    return n;
  }
  if (n < magic) {
    return ans_small[k][n];
  }
  return get_ans(n, k - 1) - get_ans(n / a[k - 1], k - 1);
}
int main() {
  ios_base::sync_with_stdio(0);
  long long n;
  int k;
  cin >> n >> k;
  for (int i = 0; i < k; ++i) {
    cin >> a[i];
  }
  sort(a, a + k);
  for (int i = 0; i < magic; ++i) {
    ans_small[0][i] = i;
  }
  for (int i = 1; i <= k; ++i) {
    for (int j = 0; j < magic; ++j) {
      ans_small[i][j] = ans_small[i - 1][j] - ans_small[i - 1][j / a[i - 1]];
    }
  }
  cout << get_ans(n, k) << endl;
  return 0;
}
