#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include "debug.h"
#else
#define debug(...) 42
#endif
const int N = 505, M = 125005;
int n;
int a[N], f[M], cnt[2 * M];
int main() {
ios::sync_with_stdio(false); cin.tie(nullptr);
cin >> n;
f[0] = 1;
for (int i = 1; i <= n; ++i) {
cin >> a[i];
for (int j = M - 1; j >= a[i]; --j) {
f[j] += f[j - a[i]];
}
}
int sum = accumulate(a + 1, a + n + 1, 0);
if (!f[sum / 2]) {
cout << 0 << "\n";
exit(0);
}
for (int i = 1; i <= n; ++i) {
sum -= a[i];
for (int j = a[i]; j < M; ++j) {
f[j] -= f[j - a[i]];
}
for (int j = 0; j <= sum / 2; ++j) {
if (f[j]) {
++cnt[sum - 2 * j];
}
}
for (int j = M - 1; j >= a[i]; --j) {
f[j] += f[j - a[i]];
}
sum += a[i];
}
int res = 0;
for (int i = 1; i < 2 * M; ++i) {
res += cnt[i] == n;
}
cout << res << "\n";
for (int i = 1; i < 2 * M; ++i) {
if (cnt[i] == n) {
cout << i << " ";
}
}
return 0;
}
