#ifdef ONPC
#define _GLIBCXX_DEBUG
#endif
#include <bits/stdc++.h>
using namespace std;
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
using ll = long long;
using ull = unsigned long long;
using ld = long double;
template<typename T1, typename T2> istream& operator>>(istream& in, pair<T1, T2>& p) {in >> p.first >> p.second; return in;}
template<typename T1, typename T2> ostream& operator<<(ostream& out, pair<T1, T2>& p) {out << p.first << ' ' << p.second; return out;}
template<typename T> istream& operator>>(istream& in, vector<T>& v) {for (auto& x : v) in >> x; return in;}
template<typename T> ostream& operator<<(ostream& out, vector<T>& v) {for (auto& x : v) out << x << ' '; return out;}
const int MAX_INT = 2147483647;
const int mod = 1e9 + 7;
const int MAXN = 250001;
int s = 0;
int n;
int ans[MAXN] = {};
vector<int> a;
vector<int> in[1 << 13];
void add(int lq, int rq, int id, int x, int l, int r) {
if (rq <= l || r <= lq) return;
if (lq <= l && r <= rq) {
in[x].push_back(id);
return;
}
int m = (l + r) / 2;
add(lq, rq, id, 2 * x + 1, l, m);
add(lq, rq, id, 2 * x + 2, m, r);
}
void calc(int x, int l, int r, bitset<MAXN>& b) {
bitset<MAXN> nb = b;
for (auto id : in[x]) b |= (b << a[id]);
if (l + 1 == r) {
if (l == n - 1) {
if (s % 2 == 1 || !b[s / 2]) {
fill(ans, ans + MAXN, 0);
}
}
if (l >= n && (l - n) % 2 == 0) {
int cur = (l - n) / 2;
for (int i = 1; i < MAXN; i++) {
if ((s - a[cur] + i) % 2 == 1 || !b[(s - a[cur] + i) / 2]) {
ans[i] = 0;
}
}
}
} else {
int m = (l + r) / 2;
calc(2 * x + 1, l, m, b);
calc(2 * x + 2, m, r, b);
}
swap(nb, b);
}
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cin >> n;
a.resize(n);
for (int i = 0; i < n; i++) {
cin >> a[i];
s += a[i];
}
for (int i = 0; i < n; i++) {
add(0, n + 2 * i, i, 0, 0, 3 * n);
add(n + 2 * i + 1, 3 * n, i, 0, 0, 3 * n);
}
fill(ans + 1, ans + MAXN, 1);
bitset<MAXN> b;
b[0] = 1;
calc(0, 0, 3 * n, b);
vector<int> good;
for (int i = 1; i < MAXN; i++) {
if (ans[i]) {
good.push_back(i);
}
}
cout << good.size() << '\n';
cout << good << '\n';
return 0;
}
