#include <bits/stdc++.h>
using namespace std;
struct Interval {
    int l, r;
    Interval(int l, int r) : l(l), r(r) {}
    bool operator<(const Interval& other) const {
        if (l != other.l) return l < other.l;
        return r < other.r;                 
    }
};
int main() {
    int n;
    cin >> n; 
    vector<Interval> intervals;
    for (int i = 0; i < n; i++) {
        int l, r;
        cin >> l >> r;
        intervals.emplace_back(l, r);
    }
    sort(intervals.begin(), intervals.end());
    for (const auto& interval : intervals) {
        cout << interval.l << " " << interval.r << endl;
    }
    return 0;
}