#include <bits/stdc++.h>

using namespace std;

const int NMax = 4e5 + 5;

int A[NMax];
int B[NMax];

int main(){
    #ifndef ONLINE_JUDGE
    freopen("a.in", "r", stdin);
    #endif // ONLINE_JUDGE

    int n, x;
    cin >> n;
    for(int i = 1; i <= n; i++){
        cin >> A[i];
        A[i] %= n;
        A[i] = (A[i - 1] + A[i]) % n;
        if(B[A[i]] == 0){
            B[A[i]] = i;
        } else {
            cout << i - B[A[i]] << "\n";
            for(int j = B[A[i]] + 1; j <= i; j++){
                cout << j << " ";
            }
            return 0;
        }
    }
    return 0;
}