#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define all(v) (v).begin(), (v).end()
int main() {
ios::sync_with_stdio(false); cin.tie(nullptr);
int n;
cin >> n;
vector<int> a(n);
for (auto &i : a)
cin >> i;
int sm = accumulate(all(a), 0);
vector<int> dp(sm + 1); dp[0] = 1;
for (auto i : a) {
for (int j = sm; j >= i; j--)
dp[j] += dp[j - i];
}
if (sm & 1 || !dp[sm >> 1]) return cout << 0, 0;
vector<int> ans(sm + 1);
for (auto i : a) {
for (int j = i; j <= sm; j++)
dp[j] -= dp[j - i];
for (int j = 1; j <= sm >> 1 && (sm - i + j) >> 1 <= sm; j++)
if (!((sm - i + j) & 1) && dp[(sm - i + j) >> 1]) ans[j]++;
for (int j = sm; j >= i; j--)
dp[j] += dp[j - i];
}
cout << count(all(ans), n) << '\n';
for (int i = 1; i <= sm; i++)
if (ans[i] == n) cout << i << ' ';
}
