#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <functional>
using namespace __gnu_pbds;
using namespace std;
typedef tree<int, null_type, less<int>, rb_tree_tag,
tree_order_statistics_node_update>
ordered_set;
//Dijkstra->set
//set.find_by_order(x) x-position value
//set.order_of_key(x) number of strictly less elements don't need *set.??
#define N 100005
#define wr cout << "Continue debugging\n";
#define all(x) (x).begin(), (x).end()
#define ll long long int
#define pii pair <int, int>
#define pb push_back
#define ff first
#define ss second
int main ()
{
ios::sync_with_stdio(false);
cin.tie(0);
int n;
cin >> n;
vector<int>a(n+1,0);
int S=0;
for (int i = 1; i <= n; i++){
cin >> a[i];
S += a[i];
}
vector<int> dp(S+1,0), can(S+1,0);
dp[0]=1;
for (int i = 1; i <= n; i++){
for (int j = S-a[i]; j >= 0; j--){
dp[j+a[i]] += dp[j];
}
}
if (S%2 or !dp[S/2]) return cout << 0, 0;
for (int i = 1; i <= n; i++){
for (int j = a[i]; j <= S; j++){
dp[j] -= dp[j-a[i]];
}
int newS = S-a[i];
for (int j = 0; j <= newS/2; j++){
if (dp[j]) can[newS-2*j]++;
}
for (int j = S-a[i]; j >= 0; j--){
dp[j+a[i]] += dp[j];
}
}
vector<int> ans;
for (int i = 1; i <= S; i++){
if (can[i] == n) ans.pb(i);
}
cout << ans.size() << '\n';
for (auto i : ans){
cout << i << " ";
}
}
