#include<bits/stdc++.h>
using namespace std;
#define rep(i, n) for(int i = 0; i < (int)(n); i++)
using ll = long long;

// グローバル変数
ll n;
vector<ll> a, b;
vector<pair<ll, ll>> ans;
ll st = 500000000000000000;

void input(){
    cin >> n;

    rep(i, n){
        ll u, v; cin >> u >> v;
        a.push_back(u);
        b.push_back(v);
    }
}

pair<ll, ll> average(int idx1, int idx2){
    return {(a[idx1]+a[idx2])/2, (b[idx1]+b[idx2])/2};
}

ll score(ll num1, ll num2){
    return max(st-num1, st-num2);
}

ll use(){
    pair<ll, ll> ret;  // s{score, idx}
    rep(i, n-1){
        pair<ll, ll> tmp = average(0, i+1);
        ll tmps = score(tmp.first, tmp.second);
        if(tmps < ret.first) ret = {tmps, i+1};
    }

    ans.push_back({1, ret.second+1});
    pair<ll, ll> c = average(0, ret.second);
    a[0] = c.first;
    a[ret.second] = c.first;
    b[0] = c.second;
    b[ret.second] = c.second;

    return ret.second;
}

void calc(){
    rep(i, 50){
        use();
    }
}

void output(){
    cout << ans.size() << endl;
    for(auto i : ans){
        cout << i.first << " " << i.second << endl;
    }
}

int main(){
    input();
    calc();
    output();
}