#include <bits/stdc++.h>
#define FOR(i, a, b) for (int i = a; i<= b; ++i)
#define FORD(i, a, b) for (int i = a; i>=b; --i)
#define REP(i, a) for (int i = 0; i<a; ++i)
#define N 555
#define pp pair<int, int>
#define bit(S, i) (((S) >> i) & 1)
#define IO cin.tie(NULL);cout.tie(NULL);
#define taskname "BOOTFALL"
using namespace std;
int n, a[N];
long long dp[N * N], newDp[N * N], cnt[N * N];
vector<int> res;
int main() {
// freopen(taskname".inp","r",stdin);
// freopen(taskname".out","w",stdout);
IO;
scanf("%d", &n);
int all = 0;
FOR(i, 1, n) scanf("%d", &a[i]);
FOR(i, 1, n) all += a[i];
int total = 0;
dp[0] = 1;
FOR(i, 1, n) {
total += a[i];
FORD(S, all, a[i]) {
if (dp[S - a[i]]) {
dp[S] += dp[S - a[i]];
}
}
}
if (all % 2 == 1 || dp[all / 2] == 0) {
printf("0");return 0;
}
// FOR(S, 0, all) if (dp[0][S]) cerr << S << ':' << dp[0][S] << endl;
FOR(i, 1, n) {
FOR(S, 0, all) newDp[S] = dp[S];
FOR(S, a[i], all) newDp[S] -= newDp[S - a[i]];
FOR(value, 1, all) {
if ((all + value - a[i]) % 2 == 1 || all - a[i] < value) {
continue;
}
int newMid = (all - a[i] + value) / 2;
if (newDp[newMid - value] == 0) {
continue;
}
cnt[value]++;
}
}
FOR(value, 1, all) {
if (cnt[value] == n) {
res.push_back(value);
}
}
printf("%d\n", res.size());
for (int value : res) printf("%d ", value);
}
