#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#define fi first
#define se second
#define ll long long
using namespace std;
const int N = 3e5 + 7;
const int mod = 1e9 + 7;
int n;
int a[N];
int d[N];
int d1[510][N];
vector < int > v[N];
void solve()
{
cin >> n;
int sum = 0;
for( int i = 1; i <= n; i++ ){
cin >> a[i];
sum += a[i];
}
d[0] = 1;
for( int i = 1; i <= n; i++ ){
for( int j = sum; j >= 0; j-- ){
if( j - a[i] >= 0 ){
d[j] += d[j - a[i]];
}
}
}
if( sum % 2 ){
cout << "0\n";
return;
}
for( int i = 1; i <= n; i++ ){
for( int j = 0; j <= sum; j++ ){
d1[i][j] = d[j];
if( j - a[i] >= 0 ){
d1[i][j] -= d1[i][j - a[i]];
}
}
}
if( !d[sum / 2] ){
cout << "0\n";
return;
}
vector < int > ans;
for( int i = 1; i <= sum; i++ ){
bool f = false;
for( int j = 1; j <= n; j++ ){
int x = sum - a[j] + i;
if( x % 2 )f = true;
if( !d1[j][x / 2] )f = true;
}
if( !f )ans.push_back(i);
}
cout << (int)ans.size() << "\n";
for( auto x : ans ){
cout << x << " ";
}
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
//freopen( "input.txt" , "r" , stdin );
//freopen( "output.txt" , "w" , stdout );
int t = 1;//cin >> t;
while( t-- ){
solve();
}
}
