#include <iostream>
#include <map>
#include <vector>

using namespace std;

const int NMAX = 400000 + 2;

map <int, int> suma;
int suma2[NMAX];
vector <int> sol;

int n;
int v[NMAX];

void citeste() {
	cin >> n;
	for (int i = 1; i <= n; ++i) {
		cin >> v[i];
		v[i] %= n;
	}
}

void gaseste_sol(int x) {
	int ant = suma2[x];
	sol.push_back(ant);
	if (v[ant] == x) return;
	int next = (x - v[ant] + n) % n;
	gaseste_sol(next);
}

void scrie() {
	gaseste_sol(0);
	
	int l = (int) sol.size();
	cout << l << '\n';
	for (int i = 0; i < l; ++i) cout << sol[i] << ' ';
	cout << '\n';
}

void rezolva() {
	int aux, val;
	map <int, int> :: iterator it;

	for (int i = 1; i <= n; ++i) {
		val = v[i];
		if (val == 0) {
			cout << "1\n" << i << '\n';
			return;
		}

		if (!suma[val]) {
			suma[val] = i;
			suma2[val] = i;
		}

		for (it = suma.begin(); it != suma.end(); ++it) {
			if ((*it).second == i) continue;
			
			aux = ((*it).first + val) % n;
			if (suma2[aux]) continue;
			suma[aux] = i;
			suma2[aux] = i;
		}

		if (suma2[0]) {
			scrie();
			return;
		}
	}
}

int main() {
	citeste();
	rezolva();


	return 0;
}