#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;

map<vector<int>, int> idx;
vector<int> stk;
vector<pair<int, int>> nvec;
vector<array<vector<int>, 31>> e(1);
int cnt = 0, sum = 0, n, m;
void getsum(int id, int x, int hd) {
    if (id == (int)stk.size()) {
        vector<int> now;
		bitset<32> f;
		f[0] = 1;
        for (auto [x, y] : nvec) {
			if (x > 0) {
            	now.emplace_back(x);
			}
			if (y > 0) {
            	now.emplace_back(y);
			}
			f = (f << x) | (f << y);
        }
        sort(now.begin(), now.end());
		int to = idx[now];
		for (int i = 0; i <= n; i++) {
			if (f[i]) {
				e[hd][i].emplace_back(to);
			}
		}
        return;
    }
    for (int i = 0; i <= stk[id] / 2; i++) {
        nvec.emplace_back(i, stk[id] - i);
        getsum(id + 1, x + i, hd);
        nvec.pop_back();
    }
}
void dfs(int res, int num) {
    if (res == 0) {
        idx[stk] = ++cnt;
        e.emplace_back();
        getsum(0, 0, cnt);
    }
    if (res < num) {
        return;
    }
    for (int x = num; x <= res; x++) {
        stk.emplace_back(x);
        dfs(res - x, x);
        stk.pop_back();
    }
}

int main(void) {
    ios::sync_with_stdio(false);
    cin.tie(nullptr), cout.tie(nullptr);
    cin >> n >> m;
    dfs(n, 1);
	vector<int> vis(cnt + 1);
	vis[idx[{n}]] = true;
	for (int i = 1; i <= m; i++) {
		int a;
		cin >> a;
		vector<int> nxt(cnt + 1);
		for (int x = 1; x <= cnt; x++) {
			if (vis[x]) {
				for (auto y : e[x][a]) {
					nxt[y] = true;
				}
			}
		}
		swap(vis, nxt);
	}
	int ans = 0;
	for (auto &[vec, id] : idx) {
		if (vis[id]) {
			int now = 0;
			for (auto x : vec) {
				now += (x == 1);
			}
			ans = max(ans, now);
		}
	}
	cout << ans << '\n';
    return 0;
}