#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define fr first
#define sc second
#define clr(a, x) memset(a, x, sizeof(a))
#define dbg(x) cout<<"("<<#x<<"): "<<x<<endl;
#define printvector(arr) for (auto it = arr.begin(); it != arr.end(); ++it) cout<<*it<<" "; cout<<endl;
#define all(v) v.begin(), v.end()
#define lcm(a, b) (a * b)/__gcd(a, b)
#define int long long int
#define printvecpairs(vec) for(auto it: vec) cout<<it.fr<<' '<<it.sc<<endl;
#define endl '\n'
#define float long double
const int MOD = 1e9 + 7;
const int INF = 2e15;
const int MAXN = 1e5 + 5;
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
#ifdef LOCAL
freopen("input.txt", "r", stdin);
#endif
int n;
cin>>n;
int a[n+2];
int sum = 0;
for(int i=1;i<=n;i++){
cin>>a[i];
sum += a[i];
}
int dp[sum+2];
clr(dp, 0);
dp[0] = 1;
for(int i=1;i<=n;i++){
for(int j=sum;j>=a[i];j--){
if(j >= a[i]) dp[j] += dp[j-a[i]];
}
}
if(dp[sum/2] == 0){
cout<<0<<endl;
return 0;
}
int cnt[sum+2];
clr(cnt, 0);
for(int i=1;i<=n;i++){
for(int j=a[i];j<=sum;j++){
dp[j] -= dp[j-a[i]];
}
int mx = sum-a[i];
for(int j=0;j<=sum;j++){
int x = 2*j-mx;
if(dp[j] != 0 && x >= 0){
cnt[x]++;
}
}
for(int j=sum;j>=a[i];j--){
dp[j] += dp[j-a[i]];
}
}
vector<int> ans;
for(int i=1;i<=sum;i++){
if(cnt[i] == n) ans.pb(i);
}
cout<<ans.size()<<endl;
printvector(ans);
return 0;
}
