gen 56

#include "testlib.h"
#include "bits/stdc++.h"
#define ll         long long
#define rep(i,a,b)    for(ll int i=a;i<b;i++)
#define pii        pair<ll,ll>
#define sz(x)      (ll)(x.size())
#define pb         push_back
#define all(a)     ((a.begin()),(a.end()))
using namespace std;

void writeTest(int test){
    startTest(test);
    /***********************************/
    unsigned seed = std::chrono::system_clock::now().time_since_epoch().count();
    mt19937_64 generator (seed);
    /***********************************/
    ll N=1000;
    ll Q=500000;
    ll V=1000000001;
    /*****************/

    // ll n=generator()%(N-1)+2;
    ll n=N;
    ll x=generator()%n+1;
    cout<<n<<" "<<1<<endl;

    rep(i,2,n+1)
    cout<<i<<" "<<i-1<<endl;
    // queue<ll>q;
    // ll cnt=n-1;
    // q.push(n);
    // while(cnt>0)
    // {
    //  ll vl=q.front();
    //  q.pop();
    //  ll ch=generator()%3+1;
    //  if(ch>=cnt)
    //  {
    //      ch=cnt;
    //  }
    //  rep(i,0,ch)
    //  {
    //      cout<<vl<<" "<<cnt<<endl;
    //      q.push(cnt);
    //      cnt--;
    //  }
    // }
}
int main(int argc, char* argv[])
{
    registerGen(argc, argv, 1);
    for(int i=56;i<=56;i++){
        writeTest(i);
    }
    return 0;
}