#include <iostream>

using namespace std;

typedef long long ll;

const ll maxn = 200000;
const ll maxa = 1000005;

ll n, A[maxa], R[maxa], C[maxa], s, res, dva = 2LL;

int main()
{
    cin >> n;
    for (ll i = 0; i < n; ++i)
        cin >> A[i], s += A[i], C[A[i]]++;

    for (ll i = 0; i < n; ++i)
    {
        if (!((s - A[i]) & 1LL))
        {
            C[A[i]]--;
            if (C[(s - A[i]) >> 1LL])
                R[res++] = i + 1LL;

            C[A[i]]++;
        }
    }

    cout << res << '\n';
    for (ll i = 0; i < res; ++i)
        cout << R[i] << ' ';
}