#include <bits/stdc++.h>
#pragma GCC optimize ("O3")

using namespace std;
using ll = long long;

int main() {
    freopen("a.in", "r", stdin), freopen("a.out", "w", stdout);
    ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    int n;
    cin >> n;
    vector<pair<ll, int>> a;
    for (int i = 0; i < n; ++i) {
        ll l, r;
        cin >> l >> r;
        a.push_back({l, -1});
        a.push_back({r, 1});
    }
    sort(a.begin(), a.end());
    for (int i = 0; i < 2 * n; ++i) {
        cout << a[i].first << " " << a[i].second << endl;
    }
    vector<ll> ans(n + 1);
    ll last = a[0].first;
    int bal = 0;
    for (int i = 0; i < 2 * n; ++i) {
        if (a[i].second == -1) {
            ++bal;
        } else {
            while (i < 2 * n && a[i].second == 1) {

            }
        }
    }
    return 0;
}