#include <bits/stdc++.h> #include <ext/pb_ds/assoc_container.hpp> #include <ext/pb_ds/tree_policy.hpp> #define bitcount __builtin_popcountll using namespace std; using namespace __gnu_pbds; using namespace chrono; signed main() { ios::sync_with_stdio(false); cin.tie(nullptr), cout.tie(nullptr); int n; cin >> n; int a[n]; for (int i = 0; i < n; cin >> a[i++]); auto oper = [&](int& x, int& y) { x ^= y; }; vector<pair<int,int>> operations; for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) if (a[i] > a[j]) { oper(a[i], a[j]); oper(a[j], a[i]); oper(a[i], a[j]); operations.emplace_back(i, j); operations.emplace_back(j, i); operations.emplace_back(i, j); } } cout << operations.size() << "\n"; for (auto [i, j] : operations) cout << i+1 << " " << j+1 << '\n'; }