#include <bits/stdc++.h>

using namespace std;

const int N = 20;

int n;
long long a[N];
vector<long long> res;

void dfs(int x, long long y, vector<long long> z) {
    if (x == n + 1) {
        res.push_back(y);
        return;
    }
    sort(z.begin(), z.end());
    if (z.back() > a[x] && y >= a[x]) {
        long long v = z.back();
        z.pop_back(), z.push_back(v - a[x]), z.push_back(v - a[x]);
        dfs(x + 1, y - a[x], z), z.pop_back(), z.pop_back(), z.push_back(v);
        int id = upper_bound(z.begin(), z.end(), a[x]) - z.begin();
        v = z[id], z.erase(z.begin() + id), z.push_back(v - a[x]), z.push_back(v - a[x]);
        dfs(x + 1, y - a[x], z), z.pop_back(), z.pop_back(), z.push_back(v);
    }
    long long ts = 0;
    for (auto v : z) ts += min(v, a[x]);
    if (ts <= y) return;
    for (auto &v : z) v = min(v, a[x]);
    dfs(x + 1, y, z);
}

signed main() {
    long long m;
    scanf("%lld%d", &m, &n);
    for (int i = 1; i <= n; ++i) scanf("%lld", &a[i]);
    dfs(1, m, {m + 1});
    sort(res.rbegin(), res.rend());
    res.erase(unique(res.begin(), res.end()), res.end());
    printf("%d\n", (int)res.size());
    for (int i = 0; i < (int)res.size(); ++i) {
        printf("%lld%c", m - res[i], " \n"[i + 1 == (int)res.size()]);
    }
    return 0;
}