#include<iostream>
#include<vector>
#include<algorithm>
#include<bitset>
using namespace std;
const int maxc = 10000;
int S;
bitset<maxc> ans;
vector<int> a;
void solve(int l,int r,bitset<maxc> b) {
if (l == r) {
bitset<maxc> q;
for (int j = 0; j < maxc; ++j) {
int needsum = (S - 2 * j - a[l]);
if (needsum < 0) continue;
if (b[j]) {
q[needsum] = 1;
}
}
ans &= q;
return;
}
int m = (l + r) >> 1;
bitset<maxc> l1, r1;
l1 = b;
r1 = b;
for (int i = l; i <= m; ++i) {
l1 |= l1 << a[i];
}
for (int i = m + 1; i <= r; ++i) {
r1 |= r1 << a[i];
}
solve(l, m, r1);
solve(m + 1, r, l1);
}
int main() {
int n;
cin >> n;
a.resize(n);
for (int i = 0; i < n; ++i) {
cin >> a[i];
S += a[i];
}
for (int i = 0; i < maxc; ++i) ans[i] = 1;
bitset<maxc> cur;
cur[0] = 1;
solve(0, n - 1, cur);
for (int i = 0; i < n; ++i) {
cur |= cur << a[i];
}
if (S % 2 || !cur[S / 2]) {
cout << 0;
return 0;
}
vector<int> answer;
for (int i = 1; i < maxc; ++i) {
if (ans[i]) answer.push_back(i);
}
cout << answer.size() << '\n';
for (auto elem : answer) cout << elem << ' ';
}
