#pragma optimize("Bismillahirrahmanirrahim")
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//Allahuekber
//ahmet23 orz...
//FatihSultanMehmedHan
//YavuzSultanSelimHan
//AbdulhamidHan
//Sani buyuk Osman Pasa Plevneden cikmam diyor.
#define author tolbi
#include<bits/stdc++.h>
#define endl '\n'
#define deci(x) int x;cin>>x;
#define decstr(x) string x;cin>>x;
#define vint(x) vector<int> x
#define cinarr(x) for (auto &it : x) cin>>it;
#define coutarr(x) for (auto &it : x) cout<<it<<" ";cout<<endl;
#define sortarr(x) sort(x.begin(), x.end())
#define sortrarr(x) sort(x.rbegin(), x.rend())
#define revarr(x) reverse(x.begin(), x.end())
#define tol(bi) (1LL<<((int)(bi)))
#define INF LONG_LONG_MAX
using namespace std;
mt19937 ayahya(chrono::high_resolution_clock().now().time_since_epoch().count());
const int MOD = 1e9+7;
int32_t main(){
int T=1;
int tno=0;
if (!T) cin>>T;
while (T-(tno++)){
deci(n);
vint(arr(n));
cinarr(arr);
int somma = 0; for (int i = 0; i < n; i++) somma+=arr[i];
vector<vector<vector<bitset<512>>>> dp(n+1,vector<vector<bitset<512>>>(somma+1,vector<bitset<512>>(2)));
vector<vector<vector<bool>>> vis(n+1,vector<vector<bool>>(somma+1,vector<bool>(2,false)));
bitset<512> dolu;
for (int i = 0; i < n; i++){
dolu[i]=true;
}
auto f = [&](int node, int crr, int flag, auto rec)->bitset<512>{
crr=abs(crr);
bitset<512> rval;
if (node==0){
if (crr==0 && flag) return dolu;
return rval;
}
if (crr>somma) return rval;
if (vis[node][crr][flag]) return dp[node][crr][flag];
vis[node][crr][flag]=true;
if (flag){
rval = (rec(node-1,crr+arr[node-1],flag,rec)|rec(node-1,crr-arr[node-1],flag,rec));
}
else {
bitset<512> kk = rval;
kk[node-1]=true;
rval|=rec(node-1,crr-arr[node-1],flag,rec);
rval|=rec(node-1,crr+arr[node-1],flag,rec);
kk&=rec(node-1,crr,1,rec);
rval|=kk;
}
return dp[node][crr][flag]=rval;
};
if (f(n,0,1,f).count()==0){
cout<<0<<endl;
continue;
}
vector<int> say;
for (int i = 1; i < somma; i++){
if (f(n,i,0,f).count()==n){
say.push_back(i);
}
}
cout<<say.size()<<endl;
coutarr(say);
}
}
