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

int main() {
	int n; cin >> n;
	vector<int> arr(n);
	for(int i = 0; i < n; i++)
	cin >> arr[i];
	
	unordered_map<int,vector<pair<int,int>>> mp;
	vector<vector<int>> res;
	for(int k = 2; k < n-1; k++){
		int j = k-1;
		for(int i = 0; i < j; i++){
			int sum = arr[i]+arr[j];
			mp[sum].push_back({i,j});
		}
		for(int l = k+1; l < n; l++){
			int target = -1*(arr[k]+arr[l]);
			if(mp.find(target)!=mp.end()){
				vector<pair<int,int>> temp = mp[target];
				for(int x = 0; x < temp.size(); x++){
					cout << temp[x].first << " " << temp[x].second << " " << k << " " << l << endl;
				}
			}
		}}
		
	
	return 0;
}