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

typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef long long LL;
typedef pair<LL, LL> PLL;

#define ALL(a)  (a).begin(),(a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define EB emplace_back
#define MP make_pair
#define SZ(a) int((a).size())
#define EACH(i,c) for(typeof((c).begin()) i=(c).begin(); i!=(c).end(); ++i)
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c) sort((c).begin(),(c).end())

#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)

#define FF first
#define SS second
template<class S, class T>
istream& operator>>(istream& is, pair<S,T>& p){
  return is >> p.FF >> p.SS;
}

const double EPS = 1e-10;
const double PI  = acos(-1.0);
const LL MOD = 1e9+7;

const int MAX = 10100;
bool prime[MAX];
int dp[MAX];

int main(){
  cin.tie(0);
  ios_base::sync_with_stdio(false);

  fill(prime, prime+MAX, true);
  for(int i=2;i*i<=MAX;++i)
	if(prime[i])
	  for(int j=i+i;j<MAX;j+=i)
		prime[j] = false;

  int M, N; cin >> M >> N;
  VI xs(N);
  REP(i,N) cin >> xs[i];
  SORT(xs);

  fill(dp, dp+MAX, -1e9);
  dp[M] = 0;
  for(int i=M-1;i>=0;--i){
	REP(j,N)
	  if(i+xs[j] <= M)
		dp[i] = max(dp[i], dp[i+xs[j]] + 1);
  }

  LL ans = 0;
  FOR(i,2,M+1) if(prime[i]) ans += max(0, dp[i]);
  ans+=*max_element(dp, dp+MAX);

  cout << ans << endl;
  
  return 0;
}