//#pragma GCC optomize ("Ofast")
//#pragma GCC optomize ("unroll-loops")
//#pragma GCC target ("avx,avx2,fma")
#include <bits/stdc++.h>
#define F first
#define S second
#define pb push_back
#define sz size
#define cl clear
#define ins insert
#define ers erase
#define pii pair < int , int >
#define pll pair< long long , long long >
#define all(x) x.begin() , x.end()
#define ios ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define file(s) if (fopen(s".in", "r")) freopen(s".in", "r", stdin), freopen(s".out", "w", stdout)
#define tostr(x) to_string(x)
#define tonum(s) atoi(s.c_str())
#define seon(x) setprecision(x)
#define bpop(x) __builtin_popcount(x)
#define deb(x) cerr << #x << " = " << x << endl;
typedef long long ll;
typedef unsigned long long ull;
typedef double db;
typedef long double ldb;
const double PI = 3.14159265;
const ll N = 500+9 , M = 258000;
const ll mod = 1e9+7;
const ll inf = 1e9;
const ll INF = 1e18;
using namespace std;
int dp[M];
int a[N];
vector<int> ans;
int cnt[M];
void solve(){
int n;
cin >> n;
ll sum = 0;
for(int i = 1; i <= n ; i++) {
cin >> a[i];
sum += a[i];
}
dp[0] = 1;
for(int i = 1; i <= n ; i++) {
for(int j = sum; j >= a[i]; j--) dp[j] += dp[j-a[i]];
}
if(sum % 2 == 1 || dp[(sum>>1)] == 0){
cout << 0;
return;
}
for(int i = 1; i <= n; i++){
for(int j = a[i]; j <= sum; j++) dp[j] -= dp[j-a[i]];
for(int x = 1; x <= sum-a[i]; x++){
int ob = sum-a[i]+x;
if(ob % 2 == 0 && dp[ob/2-x]){
cnt[x]++;
if(cnt[x] == n) ans.pb(x);
}
}
for(int j = sum; j >= a[i]; j--) dp[j] += dp[j-a[i]];
}
cout << ans.sz() <<"\n";
for(int x : ans) cout << x <<" ";
}
signed main(){
ios;
solve();
return 0;
}
/*
*/
