#include <bits/stdc++.h>
#define arr(i,n) for(ll i=0;i<n;i++)
#define ARR(i,n) for(ll i=n-1;i>=0;i--)
#define f(i,a,b)  for(ll i=a;i<b;i++)
#define F(i,a,b)  for(ll i=b-1;i>=a;i--)
#define float double
#define PI 3.14159265358979323846
#define pb push_back
#define mp make_pair
#define vi vector<ll>
#define vc vector<char>
#define ceil(a,b) ceil(a*1.0/b)
#define vpii vector< pair<ll,ll> >
#define debug(x) cout<<(#x)<<" is "<<(x)<<endl
#define gcd(a,b) __gcd(a,b)
#define lcm(a,b) (a*(b/gcd(a,b)))
#define all(v) v.begin(),v.end()
#define inputarr(a,n) for(ll i=0;i<n;++i) cin>>a[i]
#define printarr(a,n) for(ll i=0;i<n;++i) cout<<a[i]<<" "
#define integer_to_string to_string 
#define IOS  ios::sync_with_stdio(0); cin.tie(0); cout.tie(0)
typedef long long ll;
using namespace std;
const ll  mod = 1000000000 + 7;
/*freopen("input.txt","r",stdin);
freopen("output.txt","w",stdout);*/
void solve()
{
    //code start her
    ll n;
    cin>>n;
    vpii v;
    f(i,3,n)
    {
        if(i!=10&&i!=4) v.pb(mp(i,i+1));
    }
    if(n>10)
    {
        ll temp=n;
        while(temp!=1)
        {
            v.pb(mp(n,10));
            temp=ceil(temp,10);
        }
        v.pb(mp(10,4));
        v.pb(mp(10,4));
        v.pb(mp(4,2));
        v.pb(mp(4,2));
    }
    else
    {
        ll temp=n;
        while(temp!=1)
        {
            v.pb(mp(n,2));
            temp=ceil(temp,2);
        }
        if(n>4) {v.pb(mp(4,2));
        v.pb(mp(4,2));}
    }
    cout<<v.size()<<endl;
    arr(i,v.size()) cout<<v[i].first<<" "<<v[i].second<<endl;
}
int main()
{
    int t;
    cin>>t;
    while(t--)
      solve();
    return 0;
}