#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;

    for (int k = 2; k < n - 1; k++) {
        int j = k - 1;

        // Store earlier pairs (i, j).
        for (int i = 0; i < j; i++) {
            int xr = arr[i] ^ arr[j];
            mp[xr].push_back({i, j});
        }

        // Find matching pairs (k, l).
        for (int l = k + 1; l < n; l++) {
            int target = arr[k] ^ arr[l];

            auto it = mp.find(target);

            if (it != mp.end()) {
                for (auto [i, j] : it->second) {
                    cout << "[" << i + 1 << ","
                         << j + 1 << ","
                         << k + 1 << ","
                         << l + 1 << "]\n";
                }
            }
        }
    }

    return 0;
}