#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define ar array
#define fr first
#define sc second
#define vec vector
#define ret return
#define ins insert
#define mk make_pair
#define pb push_back
#define pf push_front
#define pob pop_back
#define pof pop_back
#define int long long
#define pii pair<int,int>
#define all(s) s.begin(), s.end()
#define allr(s) s.rbegin(), s.rend()
#define NeedForSpeed ios::sync_with_stdio(0),cin.tie(0);
#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
const int N=1e6+12,INF=1e9,mod = 1e9+7;
bool iswowel(char n){ n = toupper(n); if(n == 'A' || n == 'O' || n == 'U' || n == 'E' || n == 'I') return true; else return false;}
int n,m,k,x,y,l,r,o,ans,res,ok,mx,mn = INF;
int a[N],dp[N],b,c;
set<int>s;
map<int,int>mp;
main(){
NeedForSpeed
cin>>n;
for(int i=1; i<=n; i++){
cin>>a[i];
x += a[i];
}
if(n % 2){
cout<<0;
ret 0;
}
for(int j=0; j<=x; j++){
for(int i=1; i<=n; i++){
int tm = a[i];
int f = x - (a[i] - j);
a[i] = j;
dp[0] = 1;
for(int k=1; k<=n; k++){
for(int l=f-a[k]; l>=0; l--){
if(dp[l]){
dp[l+a[k]] = 1;
}
}
}
if(dp[f/2] && f % 2 == 0){
s.ins(j);
mp[j]++;
if(mp[j] >= n)res++;
}
for(int k=0; k<=f; k++)dp[k] = 0;
a[i] = tm;
}
}
cout<<res<<endl;
for(int i : s)if(mp[i] >= n)cout<<i<<" ";
return 0;
}
