#include<bits/stdc++.h>
using namespace std;
const int N = 250000;
const int M = 1000000;
const int MOD = 1e9 + 7;
int n;
int v[502];
int freq[1 + M];
bool dp[1 + N];
int dp2[1 + N];
int dp3[1 + N];
int firstVal[1 + N];
int lastVal[1 + N];
bool solve(int x){
int sum = 0;
for(int i = 1; i <= n; i++){
if(i != x){
sum += v[i];
}
}
if(x == 0){
int maxVal = 0;
dp[0] = 1;
dp2[0] = 1;
for(int i = 1; i <= n; i++){
for(int j = maxVal; j >= 0; j--){
if(dp[j]){
dp2[j + v[i]] = (dp2[j + v[i]] + dp2[j]) % MOD;
if(!firstVal[j + v[i]]){
firstVal[j + v[i]] = i;
}
lastVal[j + v[i]] = i;
dp[j + v[i]] = 1;
}
}
maxVal += v[i];
}
if(maxVal % 2 == 0 && dp[maxVal/2]){
return 1;
}
return 0;
}
else{
for(int j = 0; j <= sum + v[x]; j++){
dp3[j] = dp2[j];
}
for(int j = v[x]; j <= sum + v[x]; j++){
dp2[j] = (((dp2[j] - dp2[j - v[x]]) % MOD) + MOD) % MOD;
}
for(int i = 0; i <= sum/2; i++){
if(dp2[i]){
freq[sum - 2 * i]++;
}
}
for(int j = 0; j <= sum + v[x]; j++){
dp2[j] = dp3[j];
}
return true;
}
}
int main(){
cin >> n;
for(int i = 1; i <= n; i++){
cin >> v[i];
}
sort(v + 1, v + n + 1);
bool thing = solve(0);
if(thing == false){
cout << 0 << "\n";
return 0;
}
for(int i = 1; i <= n; i++) solve(i);
int ans = 0;
vector<int> val;
for(int i = 0; i <= M; i++){
if(freq[i] == n){
ans++;
val.push_back(i);
}
}
cout << ans << "\n";
for(int x : val){
cout << x << " ";
}
cout << "\n";
}
