#include<bits/stdc++.h>
#define ll long long
#define ull unsigned ll
#define pb push_back
#define epb emplace_back
#define f first
#define s second
#define pii pair<int,int>
#define pll pair<ll,ll>
#define inf 1e9+1
#define linf 1e18+1
using namespace std;
int dp[250001];
int d[250001];
int b[250001];
void solve(){
int n;cin>>n;
int a[n+1];
for(int i=1;i<=n;i++)cin>>a[i];
dp[0]=1;
int sum=0;
for(int i=1;i<=n;i++){
sum+=a[i];
}
if(sum&1){
cout<<0;
return;
}
for(int i=1;i<=n;i++){
for(int x=250000;x>=0;x--){
if(x>=a[i])dp[x]+=dp[x-a[i]];
}
}
if(!dp[sum/2]){
cout<<0;
return;
}
vector<int>ans;
for(int i=1;i<=n;i++){
for(int j=0;j<a[i];j++)d[j]=dp[j];
for(int j=a[i];j<=250000;j++)d[j]=dp[j]-d[j-a[i]];
for(int j=1;j<=250000;j++){
if(!d[j])continue;
int x=2*j+a[i]-sum;
if(x>0){
b[x]++;
if(b[x]==n)ans.pb(x);
}
}
}
cout<<ans.size()<<"\n";
for(int to:ans)cout<<to<<' ';
}
int main(){
ios_base::sync_with_stdio(false);cin.tie(0);
int test=1;//cin>>test;
while(test--)solve();
}
