#include <bits/stdc++.h>

using namespace std;

const int MAX_N =  400000 + 1;

int A[MAX_N];
long long sum[MAX_N];
int N;

int main()
{
    ios_base::sync_with_stdio(false);

    cin >> N;

    for (int i = 1; i <= N; ++i)
    {
        cin >> A[i];
        A[i] %= N;

        sum[i] = (sum[i - 1] + A[i]) % N;

        if (sum[i] == 0)
        {
            cout << i << "\n";

            for (int j = 1; j <= i; ++j)
                cout << j << " ";

            cout << endl;

            return 0;
        }
    }

    unordered_map<long long, int> UMap;
    UMap.reserve(1024);
    UMap.max_load_factor(0.5);

    for (int i = 1; i <= N; ++i)
    {
        auto it = UMap.find(sum[i]);

        if (it != UMap.end())
        {
            cout << i - it->second << "\n";

            for (int j = it->second + 1; j <= i; ++j)
                cout << j << " ";

            cout << endl;

            return 0;
        }

        UMap.insert({sum[i], i});
    }


    return 0;
}