#include <bits/stdc++.h>
 
#define fi first
#define se second
#define ld long double
#define pii std::pair<int, int>
#define piii std::pair<pii, pii>
#define rep(i,a) for (int i = 0; i < a; ++i)
#define per(i,a) for (int i = a - 1; i >= 0; --i)
int N;
int sum;
int a[505];
std::bitset<125001> dp[502];
bool check(int x) {
    for (int i = 1; i <= N; ++i) {
        int cur_sum = sum + x - a[i];
        if (cur_sum & 1) {
            return false;
        }
        if (!dp[i][cur_sum / 2])
            return false;
    }
    return true;
}
void solve() {
    std::cin >> N;
    for (int i = 1; i <= N + 1; ++i)
        dp[i][0] = 1;
    for (int i = 1; i <= N; ++i) {
        std::cin >> a[i];
        sum += a[i];
    }
    if (N == 1) {
        std::cout << 0 << '\n';
        return;
    }
    for (int i = 1; i <= N + 1; ++i) {
        for (int j = 1; j <= N; ++j) if (i != j) {
            dp[i] |= (dp[i] << a[j]);
        }
    }
    if ((sum & 1) || !dp[N + 1][sum / 2]) {
        std::cout << 0 << '\n';
        return;
    }
    int ans = 0;
    std::vector<int> res;
    for (int x = 1; x <= sum / 2; ++x) {
        if (check(x)) {
            ans++;
            res.push_back(x);
        }
    }
    std::cout << ans << '\n';
    for (int x : res)
        std::cout << x << ' ';
}
int main() {
    // std::freopen("input.txt", "r", stdin);
    // std::freopen("palin.inp", "r", stdin);
    // std::freopen("sushi.out", "w", stdout);
    std::ios_base::sync_with_stdio(false);
    std::cin.tie(0);
    int T = 1; 
    // std::cin >> T;
    while (T--)
        solve();
}
// 14 / 2 (87.5% Rate)
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