include <bits/stdc++.h>

using namespace std;
vector<int> A;
set<int> res;
int sum = 0;
int n;
void Try(int i,bool used[]){
if(i == n+1) return;
for(int j = 0;j<n;j++){ if(!used[j]){ used[j] = 1; sum+=A[j]; res.insert(sum); Try(i+1,used); sum-=A[j]; used[j] = 0; } } } int main() { cin>>n;
bool used[n];
memset(used,0,sizeof(used));
for(int i = 1;i<=n;i++){
int k;cin>>k;A.push_back(k);
}
Try(1,used);
cout<<res.size()<<endl;
for(int i:res) cout<<i<<" ";
}