// #pragma GCC optimize("O3") // #pragma GCC optimize("unroll-loops") #include <bits/stdc++.h> #include <ext/pb_ds/assoc_container.hpp> #include <ext/pb_ds/tree_policy.hpp> using namespace std; using namespace __gnu_pbds; template<typename T> using ordered_set = tree<T,null_type,less_equal<T>,rb_tree_tag, tree_order_statistics_node_update>; #define ll long long #define pi pair<int,int> #define vi vector<int> #define pb push_back #define all(a) a.begin(),a.end() const int mxn = 500; int arr[mxn+1]; ll dp[mxn*mxn+1]; short res[mxn*mxn+1]; void solve(){ int n; cin >> n; dp[0] = 1; int sum = 0; for(int i = 1; i <= n; i++){ cin >> arr[i]; for(int j = sum; j >= 0; j--) dp[j+arr[i]] += dp[j]; sum += arr[i]; } if(sum%2 || dp[sum/2]==0){ cout << 0; return; } for(int i = 1; i <= n; i++){ for(int j = 0; j <= sum-arr[i]; j++) dp[j+arr[i]] -= dp[j]; for(int j = (sum-arr[i])/2; j >= 0; j--){ if(dp[j] && dp[sum-arr[i]-j]) res[sum-arr[i]-2*j]++; } for(int j = sum-arr[i]; j >= 0; j--) dp[j+arr[i]] += dp[j]; } vector<int> vec; for(int i = 1; i <= sum; i++) if(res[i]==n) vec.push_back(i); cout << vec.size() << '\n'; for(auto x : vec) cout << x << ' '; } signed main(){ cin.tie(0)->sync_with_stdio(0); int t = 1; // cin >> t; while(t--){solve();} }