#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 5;
bool vis[N];
int prime[N], cnt_prime;
void init_prime(int n = N - 1) {
  for (int i = 2; i <= n; ++i) {
    if (!vis[i]) prime[++cnt_prime] = i;
    for (int j = 1; j <= cnt_prime && i * prime[j] <= n; ++j) {
      vis[i * prime[j]] = 1;
      if (i % prime[j] == 0) break;
    }
  }
}
using pii = pair<int, int>;
vector<pii> ans;
queue<int> tmp;
int main() {
  init_prime();
  int kase;
  scanf("%d", &kase);
  while (kase--) {
    int n;
    scanf("%d", &n);
    if (n < 4) {
      puts("0");
      continue;
    }
    memset(vis, 0, sizeof(vis[0]) * (n + 1));
    int _ = upper_bound(prime + 1, prime + cnt_prime + 1, n / 2) - prime;
    for (int i = _; i; --i) {
      for (int j = 3; prime[i] * j <= n; ++j)
        if (!vis[prime[i] * j]) {
          tmp.push(prime[i] * j);
          vis[prime[i] * j] = 1;
        }
      if (tmp.size() % 2 == 0 && 2 * prime[i] <= n && !vis[2 * prime[i]]) {
        tmp.push(2 * prime[i]);
        vis[2 * prime[i]] = 1;
      }
      if (tmp.size()) tmp.push(prime[i]);
      while (!tmp.empty()) {
        int a = tmp.front();
        tmp.pop();
        ans.push_back(make_pair(a, tmp.front()));
        tmp.pop();
      }
    }
    printf("%d ", ans.size());
    for (auto it = ans.begin(); it != ans.end(); ++it)
      printf("%d %d%c", it->first, it->second, " \n"[it == ans.end() - 1]);
    ans.clear();
  }
  return 0;
}