#include <bits/stdc++.h>
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2")
using namespace std;
#define int long long
#define pii pair<int,int>
#define ff first
#define ss second
#define sp << " " <<
#define all(cont) cont.begin(),cont.end()
#define vi vector<int>
const int inf = 2e18,N = 5e5+1,MOD = 1e9+7;
bitset<250001> cando[501];
int dp[250001];
void solve() {
int n;
cin >> n;
int s = 0;
bool even = 0,odd = 0;
vi a(n+1);
for (int i=1;i<=n;i++) {
cin >> a[i];
if (a[i]%2) odd = 1;
else even = 1;
s+=a[i];
}
memset(dp,-1,sizeof dp);
dp[0] = 0;
for (int i=1;i<=2*n;i++) {
int v = a[(i > n) ? (i-n) : i];
for (int j = 250000;j>=v;j--) dp[j] = max(dp[j],dp[j-v]);
dp[0] = dp[v] = i;
if (i == n && (s%2 || dp[s/2] == -1)) {
cout << 0 << '\n';
return;
}
if (i >= n) {
for (int j = 0;j<=250000;j++) {
if (i >= n && dp[j] > i-n+1) cando[(i<2*n)?(i-n+1):(1)][j] = 1;
}
}
}
if ((odd && even)) {
cout << 0 << '\n';
return;
}
vi ans;
for (int v = odd;v<=250000;v+=2) {
int fl = 1;
for (int i = 1;i<=n;i++) {
int req = (s+v-a[i])/2-v;
if (req < 0) {
fl = -1;
break;
}
if (!cando[i][req]) {
fl = 0;
break;
}
}
if (fl == 1) ans.push_back(v);
if (fl == -1) break;
}
cout << ans.size() << '\n';
for (auto it : ans) cout << it << ' ';
cout << '\n';
}
int32_t main() {
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#ifdef Dodi
freopen("in.txt","r",stdin);
freopen("out.txt","w",stdout);
#endif
int t = 1;
//cin >> t;
while (t --> 0) solve();
}
