#include"bits/stdc++.h"
using namespace std;
/*#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
template<class x>
using ordered_set = tree<x, null_type,less<x>, rb_tree_tag,tree_order_statistics_node_update>;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
//bool plc[600000];*/
const int mod=1e9+7,maxn=250000;
int occ[250005];
int good[250006],a[505];
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
int n,sum=0;
cin>>n;
for(int i=0;i<n;i++)
{
cin>>a[i];
sum+=a[i];
}
sort(a,a+n);
//reverse(a,a+n);
//plc[0]=true;
vector <int> h;
occ[0]=1;
//yes.push_back(0);
for(int i=0;i<n;i++)
{
for(int j=maxn;j>=a[i];j--)
{
occ[j]+=occ[j-a[i]];
if(occ[j]>mod)
occ[j]-=mod;
}
}
//cout<<"HI"<<endl;
if(occ[sum/2]!=0&&sum%2==0)
{
for(int k=0;k<n;k++)
{
sum-=a[k];
for(int i=a[k];i<=maxn;i++)
{
if(occ[i-a[k]]!=0){
occ[i]-=occ[i-a[k]];
if(occ[i]<0)
occ[i]+=mod;
}
}
/*for(int i=0;i<=15;i++)
{
cout<<occ[i]<<" ";
}
cout<<"\n";*/
//cout<<"HELLO"<<endl;
for(int i=sum/2;i<=sum;i++)
{
int oth=i-(sum-i);
if(oth<=0||oth>=maxn)
continue;
if(occ[i]!=0){
good[oth]++;
//cout<<oth<<" ";
//cout<<oth<<" ";
}
}
for(int i=maxn;i>=a[k];i--)
{
if(occ[i-a[k]]!=0){
occ[i]+=occ[i-a[k]];
if(occ[i]>mod)
occ[i]-=mod;
}
}
//cout<<endl;
sum+=a[k];
}
}
for(int i=1;i<=maxn;i++)
{
if(good[i]==n){
//cout<<"???"<<endl;
h.push_back(i);
}
}
cout<<h.size()<<"\n";
for(auto i : h)
cout<<i<<" ";
}
