#include<bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
#ifdef LOCAL
#include <algo/debug.h>
#else
#define debug(...) void(0)
#endif

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    ll N; cin >> N;
    vector<ll> A(N); for(int i = 0; i < N; i++) cin >> A[i];
    map<ll, ll> MP1, MP2; for(int i = 0; i < N; i++) MP2[A[i]]++;
    int s1 = 0, s2 = 0;
    for(auto&&[a, b]: MP2) {
        if(b >= 2) {
            s2++;
        }
    }
    vector<int> ans;
    for(int i = 0; i < N - 1; i++) {
        MP2[A[i]]--; MP1[A[i]]++;
        if(MP2[A[i]] == 1) s2--;
        if(MP1[A[i]] == 2) s1++;
        if(s1 == 0 && s2 == 0) {
            ans.push_back(i + 1);
        }
    }
    cout << int(ans.size()) << endl;
    for(auto&&a : ans) {
        cout << a << " ";
    }cout << endl;
}