/*
Code written by Talant I.D.
*/
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;
#define precision(n) fixed << setprecision(n)
#define pb push_back
#define ub upper_bound
#define lb lower_bound
#define mp make_pair
#define eps (double)1e-9
#define PI 2*acos(0.0)
#define endl "\n"
#define sz(v) int((v).size())
#define all(v) v.begin(),v.end()
#define rall(v) v.rbegin(),v.rend()
#define do_not_disturb ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define OK cout << "OK" << endl;
inline bool isvowel(char ch){
ch = tolower(ch);
return (ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u');
}
inline bool isprime(int n){
if(n < 2 || (n%2 == 0 && n != 2)) return false;
for(int i = 3; i*i <= n; i++)
if(n%i == 0) return false;
return true;
}
class Union{
private:
vector <int> saizu, link;
public:
Union(int n){
saizu.assign(n, 1); link.resize(n);
iota(all(link), 0);
}
int find(int n){
if(link[n] == n) return n;
return link[n] = find(link[n]);
}
int same(int a, int b){
return find(a) == find(b);
}
void unite(int a, int b){
if(same(a, b)) return;
a = find(a); b = find(b);
if(saizu[a] < saizu[b]) swap(a, b);
saizu[a] += saizu[b];
link[b] = a;
}
int getsize(int a){
return saizu[find(a)];
}
};
const int mod = 1e9+7;
ll mode(ll a){
a %= mod;
if(a < 0) a += mod;
return a;
}
ll subt(ll a, ll b){
return mode(mode(a)-mode(b));
}
ll add(ll a, ll b){
return mode(mode(a)+mode(b));
}
ll mult(ll a, ll b){
return mode(mode(a)*mode(b));
}
ll binpow(ll a, ll b){
ll res = 1;
while(b){
if(b&1) res = mult(res, a);
a = mult(a, a);
b >>= 1;
}
return res;
}
const int N = 250007;
int used[N*2], dp[N];
int main(){
do_not_disturb
int n, i, j, k;
cin >> n;
int sum = 0;
vector <int> v(n+1);
for(i = 1; i <= n; i++){
cin >> v[i];
sum += v[i];
}
sort(all(v));
dp[0] = 1;
for(i = 1; i <= n; i++){
for(j = sum; j; j--){
if(v[i] > j) break;
dp[j] += dp[j-v[i]];
}
}
if(sum&1 || !dp[sum/2]){
cout << 0 << endl;
return 0;
}
for(k = 1; k <= n; k++){
for(j = v[k]; j <= sum; j++){
dp[j] -= dp[j-v[k]];
}
for(j = (sum-v[k])/2; j <= sum-v[k]; j++){
if(dp[j] && j*2 > sum-v[k]){
used[j*2-sum+v[k]]++;
}
}
for(j = sum; j >= v[k]; j--){
dp[j] += dp[j-v[k]];
}
}
vector <int> ans;
for(i = 1; i <= sum; i++){
if(used[i] == n) ans.pb(i);
}
cout << sz(ans) << endl;
for(auto to : ans) cout << to << ' ';
return 0;
}
