#pragma GCC optimize("Ofast")

#include <bits/stdc++.h>
using namespace std;

#define all(x) begin(x), end(x)
#ifdef CKISEKI
#define safe cerr << __PRETTY_FUNCTION__ << " line " << __LINE__ << "\n";
#define debug(a...) debug_(#a, a)
#define orange(a...) orange_(#a, a)
void debug_(auto s, auto ...a) {
  cerr << "\e[1;32m(" << s << ") = (";
  int f = 0;
  (..., (cerr << (f++ ? ", " : "") << a));
  cerr << ")\e[0m\n";
}
#include <experimental/iterator>
void orange_(auto s, auto L, auto R) {
  cerr << "\e[1;33m[ " << s << " ] = [ ";
  using namespace experimental;
  copy(L, R, make_ostream_joiner(cerr, ", "));
  cerr << " ]\e[0m\n";
}
#else
#define safe ((void)0)
#define debug(...) safe
#define orange(...) safe
#endif

int main() {
  cin.tie(nullptr)->sync_with_stdio(false);


  int n, m;
  cin >> n >> m;
  vector<int> a(m);
  for (int i = 0; i < m; i++)
    cin >> a[i];


  set<long long> dp[11];

  vector<long long> wei(n + 1, 1);
  wei[0] = n;
  for (int i = 1; i <= n; i++) {
    wei[i] = n / i + 1;
  }

  vector<long long> prewei(n + 1, 1);
  for (int i = 1; i <= n; i++)
    prewei[i] = prewei[i - 1] * wei[i - 1];

  orange(all(wei));
  orange(all(prewei));

  dp[0].insert(prewei[n]);

  auto decode = [&](long long enc_v) {
    vector<int> v;
    for (int j = 1; j <= n; j++) {
      int c = enc_v / prewei[j] % wei[j];
      for (int t = 0; t < c; t++)
        v.push_back(j);
    }
    return v;
  };

  // auto v = decode(prewei[n]);
  // orange(all(v));
  // return 0;

  vector<long long> cur[31], nxt[31];

  for (int i = 0; i < m; i++) {
    for (auto enc_v : dp[i]) {

      auto v = decode(enc_v);

      for (int j = 0; j <= a[i]; j++)
        cur[j].clear();

      cur[0].push_back(0);

      // vector<size_t> sizes;
      for (size_t j = 0; j < v.size(); j++) {
        for (int x = 0; x <= a[i]; x++)
          nxt[x].clear();

        for (int y = 0; y <= v[j]; y++) {
          for (int x = 0; x + y <= a[i]; x++) {
            for (auto u : cur[x]) {
              if (y)
                u += prewei[y];
              if (v[j] - y)
                u += prewei[v[j] - y];
              // if (y)
              //   u.push_back(y);
              // if (v[j] - y)
              //   u.push_back(v[j] - y);
              // sort(all(u));
              nxt[x + y].push_back(u);
            }
          }
        }

        for (int x = 0; x <= a[i]; x++) {
          cur[x] = nxt[x];
          sort(all(cur[x]));
          cur[x].erase(unique(all(cur[x])), end(cur[x]));
        }
        // size_t s = 0;
        // for (int x = 0; x <= a[i]; x++)
        //   s += cur[x].size();
        // sizes.push_back(s);
      }

      for (auto u : cur[a[i]]) {
        dp[i + 1].insert(u);
      }
    }
    debug(dp[i].size());
  }

  debug(dp[m].size());

  int ans = 0;
  for (auto enc_v : dp[m]) {
    auto v = decode(enc_v);
    int cnt = 0;
    for (int x : v)
      if (x == 1)
        ++cnt;
    ans = max(ans, cnt);
  }
  cout << ans << '\n';

  return 0;
}