#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef __float128 ld;

#define pii pair<int, int>
#define fi first
#define se second
#define VI vector<int>
#define VII vector<vector<int> >

const int N = 500500;
const int inf = 1e9 + 100;
const ll infll = 2e18 + 500;

int p[N], a[N];

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    int n;
    cin >> n;
    for (int i = 1; i <= n; i++) cin >> a[i];
    for (int i = 1; i <= n; i++) p[i] = i;
    vector<int> ans;
    int delta = 2e9;
    while(1) {
    	int sum1 = 0, sum2 = 0;
    	ans.clear();
    	random_shuffle(p + 1, p + n + 1);
    	for (int i = 1; i <= n; i++) {
    		if (sum1 > sum2) {ans.push_back(p[i]); sum2 += a[p[i]];}
    		else {sum1 += a[p[i]];}
    	}
    	if(sum1 == sum2){
    		cout << ans.size();
    		for(auto k : ans) cout << " " << k;
    		return 0;
    			
    	}
    }

    return 0;
}