#include <bits/stdc++.h>
#define int long long
void solve() {
int n;
std::cin >> n;
std::vector<int> a(n + 1);
for(int i = 1; i <= n; i++) {
std::cin >> a[i];
}
int sum = 0;
for(int i = 1; i <= n; i++) {
sum += a[i];
}
const int N = 351 * 351 * 2;
/**
int dp[n + 1][N][n + 1];
for(int i = 0; i <= n; i++) {
for(int sum = 0; sum < N; sum++) {
for(int j = 0; j <= n; j++) {
dp[i][sum][j] = 0;
}
}
}
for(int i = 0; i <= n; i++) {
dp[0][0][i] = 1;
}
for(int i = 1; i <= n; i++) {
for(int j = 0; j <= n; j++) {
for(int sum = 0; sum < N; sum++) {
dp[i][sum][j] = dp[i - 1][sum][j];
}
if(i != j) {
for(int sum = a[i]; sum < N; sum++) {
dp[i][sum][j] |= dp[i - 1][sum - a[i]][j];
}
}
}
}**/
std::vector<int> cnt(N);
for(int j = 0; j <= n; j++) {
std::bitset<N> newdp, olddp;
olddp[0] = 1;
for(int i = 1; i <= n; i++) {
newdp = olddp;
if(i != j)
newdp |= (newdp << a[i]);
olddp = newdp;
}
for(int i = 0; i < N; i++) {
int t = sum;
if(j == 0) {
if(sum % 2 == 0 && newdp.test(sum / 2)) {
cnt[i] += 1;
}
continue;
}
t += i;
t -= a[j];
int k = 0;
if(t < N && t % 2 == 0 && newdp.test(t / 2)) {
k = 1;
}
t -= 2 * i;
if(t >= 0 && t % 2 == 0 && newdp.test(t / 2)) {
k = 1;
}
cnt[i] += k;
}
}
std::vector<int> ans;
for(int x = 0; x < N; x++) {
if(cnt[x] == n + 1) {
ans.push_back(x);
}
}
std::cout << ans.size() << "\n";
for(int i = 0; i < ans.size(); i++) {
std::cout << ans[i] << " ";
}
}
signed main() {
std::ios::sync_with_stdio(false);
std::cin.tie(nullptr);
int t = 1;
//std::cin >> t;
while (t--) {
solve();
}
return 0;
}
