#include <bits/stdc++.h>   using namespace std;   int main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     ;     int N = 1000001;     vector<int> count(N);     long long n;     cin >> n;     vector<long long> a(n), ans;     long long sum = 0, i, j, k;     for (i = 0; i < n; i++) cin >> a[i], sum += a[i], count[a[i]]++;     for (i = 0; i < n; i++)       if ((sum - a[i]) % 2 == 0 && (sum - a[i]) / 2 < N &&           (count[(sum - a[i]) / 2] > 1 ||            (count[(sum - a[i]) / 2] == 1 && a[i] != (sum - a[i]) / 2)))         ans.push_back(i + 1);     cout << ans.size() << endl;     for (auto x : ans) cout << x <<    ;     cout << endl;     return 0;   }   