#include <bits/stdc++.h>

using namespace std;

int Val[500000];
int V[500000];

int main() {
	int n, v;
	long long s = 0;
	cin >> n;

	Val[0] = 1;
	for(int i = 1; i <= n; ++i) {
		cin >> V[i];
		s += V[i];
		if(Val[s % n]) {
			cout << i - Val[s % n] + 1 << '\n';
			for(int j = Val[s % n]; j <= i; ++j) {
				cout << j << " ";
			}
			return 0;
		}
		Val[s % n] = i + 1;
	}
	return 0;
}