#include <algorithm>
#include <cstdio>
#include <cstdlib>
#include <cctype>
#include <cmath>
#include <iostream>
#include <queue>
#include <list>
#include <stack>
#include <map>
#include <numeric>
#include <set>
#include <sstream>
#include <string>
#include <vector>
using namespace std;
#define REP(i,a,n) for(int i=(a); i<(int)(n); i++)
#define rep(i,n) REP(i,0,n)
#define FOR(it,c) for(__typeof((c).begin()) it=(c).begin(); it!=(c).end(); ++it)
#define ALLOF(c) (c).begin(), (c).end()
typedef long long ll;

#define MAX_PRIME 1000000 
bool isprime[MAX_PRIME+1]; 
void init_prime(){
  fill(isprime, isprime+MAX_PRIME+1, true); 
  isprime[0] = isprime[1] = false; 
  for(int i = 2; i <= MAX_PRIME; i++) { 
    if (isprime[i]) { 
      for(int j = i*2; j <= MAX_PRIME; j += i) 
      isprime[j] = false; 
    } 
  } 
}

int dp[25][10005];

int main(){
  ios::sync_with_stdio(false);
  init_prime();

  int M, N;
  vector<int> v;
  cin >> M >> N;
  rep(i,N){
    int c;
    cin >> c;
    v.push_back(c);
  }

  rep(i,25) rep(j,10005) dp[i][j] = -1;
  dp[0][0] = 0;
  rep(i,N){
    rep(j,M+1){
      if(dp[i][j]>=0) dp[i+1][j] = max(dp[i+1][j], dp[i][j]);
      if(j-v[i]>=0 && dp[i+1][j-v[i]]>=0) dp[i+1][j] = max(dp[i+1][j], dp[i+1][j-v[i]]+1);
    }
  }

  
  
  ll ret = 0;
  ll mx = 0;
  rep(i,M+1){
    mx = max(mx, (ll)dp[N][M-i]);
    if(isprime[i] && dp[N][M-i]>=0){
      ret += dp[N][M-i];
    }
  }
  ret += mx;
  
  cout << ret << endl;
  return 0;
}