#include<bits/stdc++.h>
using namespace std;
#define int long long

int n;
int a[105];
vector<int> v[405];
const int SZ = 3000;

void build(int id, int l, int r){
    if(l == r){
        v[id].push_back(a[l]);
        v[id].push_back(0);
        return;
    }
    int mid = l + r >> 1;
    build(id*2, l, mid);
    build(id*2+1, mid+1, r);
    
    vector<int> tmp;
    for(int x: v[id*2]){
        for(int y: v[id*2+1]){
            tmp.push_back(x+y);
        }
    }
    
    sort(tmp.begin(), tmp.end());
    int n = unique(tmp.begin(), tmp.end()) - tmp.begin();
    if(n >= SZ){
        int l = n/2 - SZ/2, r = n/2 + SZ/2 - 1;
        for(int i=l;i<=r;i++){
            v[id].push_back(tmp[i]);
        }
    }
    else{
        v[id] = tmp;
    }
}

void query(int id, int l, int r, int target, vector<int>& ans){
    // cout << "query " << l << " " << r << " " << target << endl;
    if(l == r){
        if(target == a[l]) ans.push_back(l);
        assert(target == 0 || target == a[l]);
        return;
    }

    int mid = l + r >> 1;
    for(auto x: v[id*2]){
        for(int y: v[id*2+1]){
            if(x + y == target){
                query(id*2, l, mid, x, ans);
                query(id*2+1, mid+1, r, y, ans);
                return;
            }
        }
    }
}

signed main(){
    cin >> n;
    for(int i=1;i<=n;i++) cin >> a[i];
    build(1,1,n);
    bool ok = false;
    for(auto x: v[1]){
        // cout << x << " ";
        if(x == 1e9) ok = true;
    }

    // assert(ok);
    vector<int> ans;
    query(1,1,n,(int)1e9,ans);
    cout << ans.size();
    for(int x: ans){
        cout << " " << x;
    }
}