#include <bits/stdc++.h>
//#pragma GCC optimize ("unroll-loops")
//#pragma GCC optimize ("-O3")
//#pragma GCC optimize ("Ofast")
#define sz(x) ((int)x.size())
#define PB push_back
#define all(x) x.begin(),x.end()
using namespace std;
const int N = 273;
const int N2 = N * N;
const int PW = 20;
const int oo = 2e9;
bitset<N2 * 2> f[2], cle, full;
vector<int> vc;
int n, a[N], ed;
void calc(){
ed = 0;
f[0] = cle;
f[0][N2] = 1;
for (int i = 0; i < sz(vc); i++){
ed ^= 1;
int cr = a[vc[i]];
f[ed] = (f[ed ^ 1] >> cr) | (f[ed ^ 1] << cr);
}
}
int main(){
ios_base::sync_with_stdio(0); cin.tie(0);
// freopen("in.txt","r",stdin);
vc.clear();
cin >> n;
for (int i = 0; i < n; i++) {
cin >> a[i];
vc.PB(i);
}
calc();
if (f[ed][N2] == 0){
cout << 0;
return 0;
}
sort(a, a + n);
for (int i = 0; i < N2 + N2; i++)
full[i] = 1;
for (int i = 0; i < n; i++){
if (i > 0 && a[i] == a[i - 1]) continue;
vc.clear();
for (int j = 0; j < n; j++)
if (j != i)
vc.PB(j);
calc();
full &= f[ed];
}
vc.clear();
for (int i = 1; i < N2; i++)
if (full[N2 + i])
vc.PB(i);
cout << sz(vc) << '\n';
for (int x : vc)
cout << x << '\n';
return 0;
}
