// cre: Nguyen Ngoc Hung - Train VOI 2024 :>
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <unordered_set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>
#include <cstring>
#include <unordered_map>
#include <cmath>
#include <array>
#include <cassert>
#include <random>
using namespace std;
#define __nnhzzz__ signed main()
#define BIT(i,j) ((i>>j)&1LL)
#define MASK(i) (1LL<<i)
#define ALL(x) (x).begin(),(x).end()
#define SZ(x) (int)(x).size()
#define fi first
#define se second
#define ll long long
#define vi vector<int>
#define vvi vector<vi>
#define pii pair<int,int>
#define vpii vector<pii>
#define REPDIS(i,be,en,j) for(int i = (be); i<=(en); i+=j)
#define REPD(i,be,en) for(int i = (be); i>=(en); i--)
#define REP(i,be,en) for(int i = (be); i<=(en); i++)
//-------------------------------------------------------------//
const int oo = 1e9,LOG = 20,MAXN = 5e5+7,N = 250007;
const int MOD = 1e9+7,MOD1 = 1e9+207,MOD2 = 1e9+407,MOD3 = 998244353;
//-------------------------------------------------------------//
template<typename T1, typename T2> bool mini(T1 &a, T2 b){if(a>b){a=b;return true;}return false;}
template<typename T1, typename T2> bool maxi(T1 &a, T2 b){if(a<b){a=b;return true;}return false;}
template<typename T> T gcd(T a, T b) { while(b) { a %= b; swap(a,b); } return a; }
template<typename T> T lcm(T a, T b) { return a/gcd(a,b)*b; }
/*
----------------------------------------------------------------
END OF TEMPLATE
----------------------------------------------------------------
Nguyen Ngoc Hung - nnhzzz
Training for VOI24 gold medal
----------------------------------------------------------------
*/
void solve(){
int s = 0,n; cin >> n;
vi a(n+1);
bitset<N> tmp; tmp[0] = 1;
REP(i,1,n){
cin >> a[i];
s += a[i];
tmp |= tmp<<a[i];
}
if(s%2==1 || tmp[s/2]==0){
// cerr << 0;
cout << 0; return ;
}
vi res;
// REP(k,1,s){
// int ok = 1;
// REP(j,1,n){
// int t = s-a[j]+k;
// if(t%2==1){
// ok = 0; break;
// }
// bitset<N> dp(0); dp[0] = dp[k] = 1;
// REP(i,1,n){
// if(i==j) continue;
// dp |= dp<<a[i];
// }
// if(dp[t/2]==0){
// ok = 0; break;
// }
// }
// if(ok==1) res.push_back(k);
// }
vi dp(N+3,0),ok(N+3,1); dp[0] = 1;
REP(i,1,n){
REPD(j,s,a[i]){
dp[j] += dp[j-a[i]];
}
}
REP(ii,1,n){
int x = a[ii];
REP(i,x,s) dp[i] -= dp[i-x];
REP(i,1,s){
int t = s-x+i;
if(t%2==1 || dp[t/2]==0){
ok[i] = 0;
}
}
REPD(i,s,x) dp[i] += dp[i-x];
}
REP(i,1,s){
if(ok[i]==1){
res.push_back(i);
}
}
cout << SZ(res) << "\n";
for(auto &i:res){
cout << i << " ";
}
}
__nnhzzz__{
ios::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
#define name "test"
if(fopen(name".inp","r")){
freopen(name".inp","r",stdin);
freopen(name".out","w",stdout);
}
#define name1 "nnhzzz"
if(fopen(name1".inp","r")){
freopen(name1".inp","r",stdin);
freopen(name1".out","w",stdout);
}
int test = 1;
while(test--){
solve();
}
cerr << "\nTime elapsed: " << 1000*clock()/CLOCKS_PER_SEC << "ms\n";
return 0;
}
