#include <bits/stdc++.h>

using namespace std;

vector<bool> psieve(int n) {
  vector<bool> pr(n);
  for (int i = 2; i < n; i++)
    pr[i] = true;
  for (int i = 2; i * i < n; i++) {
    if (!pr[i]) continue;
    for (int j = i * i; j < n; j += i)
      pr[j] = false;
  }
  return pr;
}

int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  
  int m, n;
  cin >> m >> n;
  vector<int> c(n);
  for (int i = 0; i < n; i++)
    cin >> c[i];

  vector<bool> pr = psieve(m);
  vector<int> dist(m + 1, -1);
  dist[0] = 0;
  for (int i = 1; i <= m; i++) {
    for (int j = 0; j < n; j++) {
      if (i - c[j] >= 0 && dist[i-c[j]] >= 0) {
        dist[i] = max(dist[i], dist[i-c[j]] + 1);
      }
    }
  }

  int ret = m / *min_element(c.begin(), c.end());
  for (int i = 1; i < m; i++) {
    if (pr[i] && dist[m-i] > -1) {
      ret += dist[m-i];
    }
  }
  
  cout << ret << endl;
  
  return 0;
}