#include <iostream>
#include <vector>
#include <utility>
#include <algorithm>
#include <set>
#define INF 2000000000
using namespace std;

#define BEGIN true
#define END false

#define CIVN(i) timeline[i].second
#define IS_BEGIN(i) (timeline[i].first.second == BEGIN)
#define IS_END(i) (timeline[i].first.second == END)
#define TIME(i) (timeline[i].first.first)

int N;
vector< pair<pair<int, bool>, int> > timeline;

int main() {
    cin >> N;
    for (int i = 0; i < N; i++) {
                int i1, i2;
                cin >> i1 >> i2;
                if (i1 != i2) {
                        timeline.push_back(make_pair(make_pair(i1, BEGIN), i));
                        timeline.push_back(make_pair(make_pair(i2, END), i));
                }
    }
    sort(timeline.begin(), timeline.end());
    int c = 0;
    int min_interval = INF;
    int result1, result2;
    int background = -1;
        int prev_background;
    for (int i = 0; i < timeline.size(); i++) {
                if (IS_BEGIN(i)) {
                        prev_background = background;
                        background = CIVN(i);
                        c++;
                }
                else {
                        c--;
                        if (c == 0) continue;
                        if (IS_END(i-1)) continue;
                        int nv = TIME(i) - TIME(i-1);
                        if (nv != 0 && nv < min_interval) {
                                result1 = CIVN(i);
                                if (CIVN(i) == CIVN(i-1))
                                        result2 = prev_background;
                                else result2 = CIVN(i-1);
                                min_interval = nv;
                        }
                }
    }
    if (min_interval == INF)
                cout << 0 << endl;
    else {
                cout << min(result1, result2) + 1 << ' ' << max(result1, result2) + 1 << endl;
    }
    return 0;
}