#include <bits/stdc++.h>
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
//#define int long long
using namespace std;
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx,bmi,bmi2,lzcnt,popcnt")
using ll = long long;
using ull = unsigned long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
const int mod = 1e9 + 7;
const int LOG = 20;
const int maxn = 1e5 + 5;
const double eps = 1e-9;
bitset<40005> bs[405];
int32_t main() {
ios_base::sync_with_stdio(false);
cout.tie(0); cin.tie(0);
int n, sum = 0;
cin >> n;
vector<int> v(n);
bs[0][0] = 1;
for(int &x : v) {
cin >> x;
sum += x;
bs[0] |= (bs[0] << x);
}
if(sum % 2 == 1 || !bs[0][sum/2]) {
cout << 0 << '\n';
return 0;
}
for(int i=0; i<n; i++) {
bs[i+1][0] = 1;
for(int j=0; j<n; j++)
if(i != j) bs[i+1] |= (bs[i+1] << v[j]);
// cout << i << ": ";
// for(int j=0; j<=10; j++) if(bs[i+1][j]) cout << j << " ";
// cout << '\n';
}
vector<int> ans;
for(int j=1; j<20005; j++) {
bool ok = 1;
for(int i=1; i<=n; i++) {
if( (sum - v[i-1] + j) % 2 == 1 ) ok = 0;
if( (bs[i][(sum - v[i-1] + j) / 2]) == 0 ) ok = 0;
}
if(ok) ans.push_back(j);
}
cout << ans.size() << '\n';
for(int &x : ans) cout << x << " ";
return 0;
}
