#include "bits/stdc++.h" using namespace std; #ifdef duc_debug #include "bits/debug.h" #else #define debug(...) #endif const int maxn = 505; const int N = 500 * 500 + 5; int n, a[maxn]; bitset<N> bs; int cnt[N]; void solve() { cin >> n; bs[0] = 1; int sum = 0; for (int i = 1; i <= n; ++i) { cin >> a[i]; bs |= (bs << a[i]); sum += a[i]; } if (sum & 1 || !bs[sum / 2]) { cout << 0; return; } for (int i = 1; i <= n; ++i) { bs = 0; bs[0] = 1; for (int j = 1; j <= n; ++j) { if (i == j) continue; bs |= (bs << a[j]); } for (int j = (sum - a[i]) / 2; j >= 0; --j) { if (bs[j]) { ++cnt[(sum - a[i]) - j * 2]; } } } vector<int> res; for (int i = 1; i < N; ++i) { if (cnt[i] == n) res.push_back(i); } cout << (int)res.size() << '\n'; for (auto i : res) cout << i << " "; } signed main() { ios_base::sync_with_stdio(0); cin.tie(0); solve(); return 0; }