#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef double ld;
typedef pair<ll,ll> ii;
typedef vector<ll> vi;
#define PB push_back()
#define ff first
#define ss second
#define MP make_pair
#define FOR(p,a,b) for(ll p = (a); p < (ll)(b); ++p)
#define F(a) FOR(i, 0, a)
#define FF(a) FOR(j, 0, a)
#define FFF(a) FOR(k, 0, a)
#define EPS (1e-10)
#define EQ(a,b) (fabs(a-b) <= fabs(a-b)*EPS)
#define DEB(x) cerr << " >>> " << #x << " : " << x << "\n"

ii pole[1001];

int main()
{
    auto cmp = [](ii a, ii b) { return (a.ff < b.ff);};
    ios::sync_with_stdio(false);
    priority_queue<ii, std::vector<ii>, decltype(cmp)> halda(cmp);
    ll n,a,b;
    cin >> n;
    F(n-1) cin >> a >> b;
    F(n) cin >> a >> b, halda.push(MP(a,i));
    F(n-1)
    {
        cout << halda.top().ss << " ";
        halda.pop();
        cout << halda.top().ss << "\n";
    }
    return 0;
}