//GIVE ME AC!!!!!!!!!!!!!!!!!
//#pragma GCC target("avx")
//#pragma GCC optimize("O3")
//#pragma GCC optimize("unroll-loops")
#include<bits/stdc++.h>
using namespace std;
random_device seed_gen;
mt19937 engine(seed_gen());
int rand_int(int l,int r){return l+engine()%(r-l);}
int t=3600,r=4;
int n,cnt=0;
vector<int>s;
void input(){
  int _;
  cin>>_>>_;
}
void input_query(){
  cin>>n;
  s.clear();
  s.resize(n);
  for(int i=0;i<n;i++)cin>>s[i];
}
int main(){
  input();
  while(t--){
    input_query();
    vector<pair<int,int>>v;
    for(int i=0;i<n;i+=4){
      for(int j=1;j<3&&i+j<n;j++){
        v.emplace_back(cnt+i+1,cnt+i+j+1);
      }
    }
    cout<<v.size()<<endl;
    for(auto &x:v)cout<<x.first<<" "<<x.second<<endl;
    cnt+=n;
  }
}