#pragma GCC optimize("O3,unroll-loops")
#include <bits/stdc++.h>
using namespace std;
#define f first
#define s second
#define pb push_back
#define ld long double
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define vec vector
using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
mt19937_64 gen(chrono::steady_clock::now().time_since_epoch().count());
const ld eps = 1e-6;
const int mod = 998244353;
const int oo = 2e9;
const ll OO = 2e18;
const int N = 250001;
void backpack(bitset<N> &can, vec<int> &a, int l, int r)
{
can.reset();
can[0] = 1;
for (int i = l; i <= r; i++) can |= can << a[i];
}
void solve()
{
int n;
cin >> n;
vec<int> a(n + 1);
int s = 0;
for (int i = 1; i <= n; i++) cin >> a[i], s += a[i];
bitset<N> base, start, end;
backpack(base, a, 1, n);
if (!base[s / 2])
{
cout << 0;
return;
}
backpack(start, a, 1, n / 2);
backpack(end, a, n / 2 + 1, n);
vec<int> cnt(500 * n + 1);
for (int i = 1; i <= n; i++)
{
bitset<N> can;
if (i <= n / 2)
{
can = end;
for (int j = 1; j <= n / 2; j++) if (j != i) can |= can << a[j];
}
else
{
can = start;
for (int j = n / 2 + 1; j <= n; j++) if (j != i) can |= can << a[j];
}
int from = (s - a[i]) % 2 ? 1 : 2;
for (int j = from; j <= 500 * n; j += 2)
{
if (can[(s - a[i] + j) / 2]) cnt[j]++;
}
}
vec<int> ans;
for (int i = 1; i <= 500 * n; i++) if (cnt[i] == n) ans.pb(i);
cout << sz(ans) << "\n";
for (int &x : ans) cout << x << " ";
}
int32_t main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
solve();
return 0;
}
