// Problem: B - first BRICK at stonewall
// Contest: Virtual Judge - ABCDE4
// URL: https://vjudge.net/contest/748359#problem/B
// Memory Limit: 1024 MB
// Time Limit: 1000 ms
//
// Powered by CP Editor (https://cpeditor.org)
# include <bits/stdc++.h>
using namespace std;
#define int long long
int n,a[1000005],t,dp[1000005],cnt[1000005];
vector<int> res;
signed main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
cin >> n;
for (int i = 1; i <= n; i++)
{
cin >> a[i];
t += a[i];
}
dp[0] = 1;
for (int i = 1; i <= n; i++)
{
for (int j = t; j >= a[i]; j--)
{
dp[j] += dp[j-a[i]];
}
}
// cout << t << " " << dp[t/2] << "\n";
if (t%2!=0 or !dp[t/2])
{
cout << 0;
return 0;
}
// cout << dp[3] << "\n";
for (int i = 1; i <= n; i++)
{
for (int j = a[i]; j <= t; j++)
{
dp[j] -= dp[j-a[i]];
}
t -= a[i];
for (int j = 0; j <= t/2; j++)
{
// if (t-2*j==3)
// {
// cout << t << " "<<i << " " << j<< " " << dp[j] << "\n";
// }
if (dp[j]) cnt[t-2*j]++;
}
t += a[i];
for (int j = t; j >= a[i]; j--)
{
dp[j] += dp[j-a[i]];
}
}
for (int i = 1; i <= t; i++)
{
if (cnt[i]==n)
{
res.push_back(i);
}
}
cout << res.size() << "\n";
for (int i = 0; i < (int)res.size(); i++)
{
cout << res[i] << " ";
}
}
