/*
*/
#include <iostream>
#include <vector>
using namespace std;
void print(const vector<int>& vec) {
for (int i=0; i<vec.size(); i++) {
cout << vec[i] << ' ';
}
cout << '\n';
}
int main() {
int n;
cin >> n;
vector<int> w(n+1, 0);
int max_x = 0;
for (int i=0; i<n; i++) {
cin >> w[i];
max_x += w[i];
}
vector<int> res;
// cout << max_x << '\n';
// iterate through possible x
for (int x=1; x<=max_x; x++) {
// cout << "x = " << x << '\n';
// fix x
w[n] = x;
max_x += x;
// print(w);
vector<int> dp(max_x + 1, 0);
dp[0] = 1;
// add everything to knapsack
for (int i=0; i<=n; i++) {
for (int s=max_x; s>=w[i]; s--) {
dp[s] += dp[s-w[i]];
}
}
// print(dp);
bool friendly = true;
for (int i=0; i<=n; i++) {
if (!friendly) break;
int max_s = max_x - w[i];
if (max_s%2 != 0) {
// cout << max_s << " is not even, cannot split\n";
friendly = false;
break;
}
// remove w[i]
// cout << "removed " << w[i] << '\n';
for (int s=w[i]; s<=max_x; s++) {
dp[s] -= dp[s - w[i]];
}
int half = max_s / 2;
if (dp[half] > 0) {
// cout << "We can split " << max_s << " in half\n";
} else {
// cout << " We cannot split " << max_s << " in half\n";
friendly = false;
}
// print(dp);
// add back w[i]
for (int s=max_x; s>=w[i]; s--) {
dp[s] += dp[s - w[i]];
}
// cout << "added back " << w[i] << '\n';
}
if (friendly) {
// cout << x << " is friendly\n";
res.push_back(x);
}
// print(dp);
max_x -= x;
}
cout << res.size() << '\n';
for (int i=0; i<res.size(); i++) {
cout << res[i] << ' ';
}
cout << '\n';
return 0;
}
