#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf32 1000000001
#define Inf64 1000000000000000001


int main(){
	int n;cin>>n;
	
	map<int,vector<int>> mp;
	rep(i,n){
		int a;
		cin>>a;
		mp[a].push_back(i);
	}
	
	int l = 0,r = n-1;
	for(auto a:mp){
		if(a.second.size()>=3){
			cout<<0<<endl<<endl;
			return 0;
		}
		if(a.second.size()==2){
			l = max(l,a.second[0]);
			r = min(r,a.second[1]);
		}
	}
	if(r-l<=0){
		cout<<0<<endl<<endl;
		return 0;
	}
	cout<<r-l<<endl;
	for(int i=l;i<r;i++){
		if(i!=l)cout<<' ';
		cout<<i+1;
	}
	cout<<endl;
	return 0;
}