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

#define rep(i,n) for(int i=0;i<n;i++)
#define reps(i,m,n) for(int i=m;i<n;i++)

typedef long long ll;
typedef unsigned long long ull;
typedef unsigned int uint;
typedef vector<int> vec;
typedef vector<vec> mat;
static const double EPS = 1e-9;
static const double PI = acos(-1.0);
const int INF = 1e9;
const int mod = 1e9 + 7;

const int MAX = 10010;
int dp[MAX][MAX] = {0};
int W[MAX];

int L, N;

int rec(int l, int n){
    if(l > L || n > N) return -1;
    if(dp[l][n] > 0){
        return dp[l][n];
    }
    int& res = dp[l][n];
    res = max(rec(l, n+1), 1+rec(l+W[n], n+1));
    return res;
}

int main(){
    cin >> L >> N;
    rep(i, N) cin >> W[i];
    cout << rec(0, 0) << endl;
    return 0;
}