#pragma GCC optimize ("Ofast")
// #pragma GCC target ("avx2")
#include <iostream>
#include <bitset>
#include <vector>
#define X first
#define Y second
#define ll long long
#define MP make_pair
using namespace std;
const int N = 500;
const ll mod = 1e9 + 7;
typedef bitset<N * N + 1> DP;
int n, sum, w[N];
int ans[N * N + 1];
DP cur;
void rec(int l, int r, DP cur) {
if(r - l == 1) {
for(int i = 0, j = sum - w[l];i <= j;i++, j--) {
if(cur[i]) ans[j - i] += 1;
}
}
else {
DP L = cur, R = cur;
int m = (l + r) / 2;
for(int i = l;i < r;i++) {
if(i >= m)
R |= R << w[i];
else
L |= L << w[i];
}
rec(l, m, R), rec(m, r, L);
}
}
int main() {
ios::sync_with_stdio(0);
cin.tie(0), cout.tie(0);
cin >> n;
for(int i = 0;i < n;i++)
cin >> w[i], sum += w[i];
DP cur = 1;
for(int i = 0;i < n;i++)
cur |= cur << w[i];
if(cur[sum / 2] == 0) return cout << "0", 0;
rec(0, n, DP(1));
vector< int > res;
for(int i = 0;i < N * N + 1;i++)
if(ans[i] == n)
res.push_back(i);
cout << res.size() << "\n";
for(int i: res)
cout << i << " ";
return 0;
}
