#include <bits/stdc++.h>
#define all(X) X.begin(), X.end()
#define sz(x) (int)x.size()
#define fr first
#define sc second
#define endl '\n'
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;
const int maxn = 1e6 + 10;
const int maxa = 1e6;
const int inf = 2e9;
const ll INF = 1e18;
const ll mod = 1e9 + 7;
const int block = 350;
int main ()
{
ios_base::sync_with_stdio(0); cin.tie();
/*#ifndef ONLINE_JUDGE
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#endif*/
int n; cin >> n;
vector <int> a (n);
int mx = 0;
for (int i = 0; i < n; i++) {
cin >> a[i];
mx = max(mx, a[i]);
}
bitset <25100> st;
int sum = 0;
st[0] = 1;
for (int i = 0; i < n; i++) {
st |= (st << a[i]);
sum += a[i];
}
if ((sum & 1)) {
cout << 0;
return 0;
} else if (!st[sum >> 1]) {
cout << 0;
return 0;
}
vector <bitset <500*500+1>> t (n);
for (int sk = 0; sk < n; sk++) {
t[sk][0] = 1;
for (int j = 0; j < n; j++) {
if (j != sk) {
t[sk] |= (t[sk] << a[j]);
}
}
}
vector <int> ans;
for (int i = 1; i <= n * mx; i++) {
sum += i;
bool ok = true;
for (int j = 0; j < n; j++) {
bitset <500*500+1> tt = t[j];
tt |= (tt << i);
sum -= a[j];
if ((sum & 1)) {
ok = false;
sum += a[j];
break;
} else if (!tt[sum >> 1]) {
ok = false;
sum += a[j];
break;
} else {
sum += a[j];
}
}
sum -= i;
if (ok) ans.push_back(i);
}
cout << sz(ans) << endl;
for (auto i : ans) {
cout << i << " ";
}
return 0;
}
