#include <bits/stdc++.h>
using namespace std;
int t, n;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cin >> t;
  while (t--) {
    cin >> n;
    cout << 2 << endl;
    cout << n << ' ' << n - 1 << endl;
    for (int i = n; i >= 3; i--) cout << i << " " << i - 2 << endl;
  }
  cout.flush();
  return 0;
}
