#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#define pb push_back
#define int long long
#define repp(i,x,n) for(int i=x;i<=n;i++)
#define rep(i,x,n) for(int i=x;i>=n;i--)
#define r0 return 0
#define fi first
#define se second
#define liow ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL)
#define jelek cout<<"jelek"<<endl
#define pii pair<int,int>
#define all(v) v.begin(),v.end()
#define tp tuple<int,int,int>
#define fl fflush(stdout)
#define ld long double
#define p5 pair<int,pair<pair<int,int>,pair<int,int>>>
#pragma GCC optimize ("O2")
#pragma GCC optimize ("unroll-loops")
using namespace std;
using namespace __gnu_pbds;
typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;
typedef tree<pair<int,int>, null_type, less<pair<int,int>>, rb_tree_tag, tree_order_statistics_node_update> ordered_multiset;
//const int mod=1e9+7;
const int SQMAX=635,INF=1e18;
const int mod=998244353;
//const int MOD=1e6+3;
mt19937_64 rng((unsigned int) chrono::steady_clock::now().time_since_epoch().count());
pii dr[8]={{-1,0},{-1,1},{0,1},{1,1},{1,0},{1,-1},{0,-1},{-1,-1}};
int dx[4]={1,0,-1,0};
int dy[4]={0,1,0,-1};
int dxx[4]={1,1,-1,-1};
int dyy[4]={1,-1,-1,1};
int mul(int x,int y){return (x%mod*y%mod)%mod;}
int expo(int b,int e){
if(e==0) return 1;
int tmp=expo(b,e/2);
if(e%2) return mul(tmp,mul(tmp,b));
else return mul(tmp,tmp);
}
const int maxn=4e5;
int a[505];
int freq[250005],dp[250005],dp2[250005];
int n;
void cek(int x){
int tot=0;
repp(i,1,n) tot+=a[i];
tot-=a[x];
repp(i,0,tot+a[x]) dp2[i]=dp[i];
repp(i,a[x],tot+a[x]){
dp[i]-=dp[i-a[x]];
}
repp(i,0,tot/2){
if(dp[i]){
freq[tot-2*i]++;
}
}
repp(i,0,tot+a[x]){
dp[i]=dp2[i];
}
}
void solve(){
cin>>n;
repp(i,1,n) cin>>a[i];
int tot=0;
repp(i,1,n) tot+=a[i];
if(tot%2==1){
cout<<0<<endl;
return;
}
dp[0]=1;
repp(i,1,n){
for(int w=tot;w>=a[i];w--){
dp[w]+=dp[w-a[i]];
}
}
if(dp[tot/2]==0){
cout<<0<<endl;
return;
}
repp(i,1,n){
cek(i);
}
vector<int>ans;
repp(i,1,250000){
if(freq[i]==n){
ans.pb(i);
}
}
cout<<ans.size()<<endl;
for(auto x:ans) cout<<x<<" ";
cout<<endl;
}
signed main(){
liow;
int t=1;
//cin>>t;
while(t--){
solve();
}
}
