#include "bits/stdc++.h"
using namespace std;
#define int long long
#define FOR(i, a, b) for(int i=(a);i<(b);i++)
#define RFOR(i, a, b) for(int i=(b-1);i>=(a);i--)
#define REP(i, n) for(int i=0; i<(n); i++)
#define RREP(i, n) for(int i=(n-1); i>=0; i--)
#define ALL(a) (a).begin(),(a).end()
#define UNIQUE_SORT(l) sort(ALL(l)); l.erase(unique(ALL(l)), l.end());
#define CONTAIN(a, b) find(ALL(a), (b)) != (a).end()
#define array2(type, x, y) array<array<type, y>, x>
#define vector2(type) vector<vector<type> >
#define out(...) printf(__VA_ARGS__)

int dxy[] = {0, 1, 0, -1, 0};

void solve();
signed main()
{
#if DEBUG
    std::ifstream in("input.txt");
    std::cin.rdbuf(in.rdbuf());
#endif
    cin.tie(0);
    ios::sync_with_stdio(false);
    solve();
    return 0;
}

/*================================*/

#if DEBUG
#define SIZE 12340
#else
#define SIZE 12340
#endif

int N,M,Q;
int C[30];
vector<int> DP(SIZE,0);

void solve() {
    cin>>M>>N;
    REP(i,N)cin>>C[i];
    
    int ans = 0;
    RREP(j,M+1) REP(i,N) {
        int c = C[i];
        if (j<c) continue;
        if (j!=M && DP[j]==0) continue;
        DP[j-c] = max(DP[j-c], DP[j]+1);
        ans = max(ans, DP[j-c]);
    }
    vector<int> primes;
    FOR(n,2,M+1) {
        bool is_prime = true;
        for (auto p:primes) if (n%p==0) {
            is_prime = false;
            break;
        }
        if (is_prime) {
            primes.push_back(n);
            ans += DP[n];
        }
    }
    cout << ans << endl;
}