#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
#define bug cout << "bug" << endl
#define speed ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0)
#define all(x) x.begin(), x.end()
#define F first
#define S second
#define pll pair <ll, ll>
#define pii pair <int, int>
#define triple pair <pair <ll, ll> , ll>
#define ull unsigned long long
#define ld long double
#define pinode pair <node*, node*>
const ll INF = 9e18 + 5;
const ll inf = 1e9 + 5;
const ll N = 5e2 + 5;
const ll shift = 2e6;
const ll mod = 1e9 + 7;
const ll M = 255000 + 5;
const ll LOG = 21;
const ll sp = 263;
const ll block = 500;
const double eps = 1e-10;
ll n, a[N], dp[M], acc = 0, cnt[M];
int main(){
speed;
cin >> n;
for(int i = 1; i <= n; i++){
cin >> a[i];
acc += a[i];
}
dp[0] = 1;
for(int i = 1; i <= n; i++){
for(int sum = M - 5; sum >= a[i]; sum--){
dp[sum] += dp[sum - a[i]];
}
}
if(acc % 2 != 0 || dp[acc / 2] == 0){
cout << 0 << endl;
return 0;
}
for(int i = 1; i <= n; i++){
for(int sum = a[i]; sum <= M - 5; sum++){
dp[sum] -= dp[sum - a[i]];
}
acc -= a[i];
for(int sum = 0; sum <= M - 5; sum++){
if(dp[sum]){
int ost = acc - sum;
if(ost - sum < 0)
continue;
cnt[ost - sum]++;
}
}
acc += a[i];
for(int sum = M - 5; sum >= a[i]; sum--){
dp[sum] += dp[sum - a[i]];
}
}
vector <int> ans;
for(int i = 0; i <= M - 5; i++){
if(cnt[i] == n)
ans.pb(i);
}
cout << ans.size() << endl;
for(auto to : ans)
cout << to << " ";
}
/*
%I64d
%I64d
*/
