#include <bits/stdc++.h>
//#include <ext/pb_ds/detail/standard_policies.hpp>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
//#pragma GCC optimize("Ofast")
//#pragma GCC target("avx2")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4")
using namespace std;
//using namespace __gnu_pbds;
//template <typename T> using ordered_set = tree <T, null_type, less < T >, rb_tree_tag, tree_order_statistics_node_update>;
mt19937 gen(time(0));
#define ll long long
#define ld long double
#define pb push_back
#define F first
#define S second
#define TIME clock() * 1.0 / CLOCKS_PER_SEC
#define sz(a) int32_t(a.size())
#define endl '\n'
//#define int long long
const int N = 250100;
const int M = 31;
const int mod = 1e9 + 7;
const ll inf = 1e18 + 7;
int dp[N], ans[N], a[510];
bool cnt[N];
int32_t main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
#ifdef LOCAL
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#else
// freopen("input.txt", "r", stdin);
// freopen("output.txt", "w", stdout);
#endif // LOCAL
int n;
cin >> n;
int sum = 0;
for(int i = 0; i < n; i++)
{
cin >> a[i];
sum += a[i];
}
dp[0] = 1;
for(int i = 0; i < n; i++)
{
for(int j = N - 1; j >= a[i]; j--)
dp[j] += dp[j - a[i]];
}
if (sum % 2 || !dp[sum / 2])
{
cout << 0;
return 0;
}
for(int i = 0; i < n; i++)
{
for(int j = a[i]; j < N; j++)
dp[j] -= dp[j - a[i]];
for(int j = N - 1; j >= 0; j--)
{
if (!dp[j]) continue;
int x = j, y = sum - j - a[i];
cnt[abs(x - y)] = 1;
}
for(int i = 0; i < N; i++)
{
if (cnt[i]) ans[i]++;
cnt[i] = 0;
}
for(int j = N - 1; j >= a[i]; j--)
dp[j] += dp[j - a[i]];
}
vector < int > ot;
for(int i = 1; i < N; i++)
if (ans[i] == n) ot.pb(i);
cout << sz(ot) << endl;
for(auto to: ot)
cout << to << " ";
}
