// UUID: 0ed492d9-baae-4244-a12b-97da0228bb99
#include <bits/stdc++.h>
using namespace std;

vector<vector<int>> fa;
vector<int> mely (4,0);
int melyseg = 0;

void bej (int ind) {
    melyseg++;
    for (int u : fa[ind]) {
        bej(u);
    }
    //cout << melyseg << endl;
    mely[ind] = melyseg;
    melyseg--;
}

int main() {
	int n;
    cin >> n;
    fa.resize(n+1);
    mely.resize(n+1);
    vector<bool> fo (n+1,true);
    for (int i = 0; i < n; i++) {
        int a, b;
        cin >> a >> b;
        fo[b] = false;
        fa[a].push_back(b);
        //fa[b].push_back(a);
    }
    int fofa;
    //vector<bool> gyer (n,false);
    for (int i = 1; i <= n; i++) {
        if (fo[i] == true) {
            fofa = i;
        }
        /*if (fa[i].size() == 1) {
            gyer[i] = true;
        }*/
    }
    bej(fofa);
    int maxmely = 0;
    int maxi = 0;
    for (int i = 1; i <= n; i++) {
        if (mely[i] > maxmely) {
            maxmely = mely[i];
            maxi = i;
        }
    }
    cout << maxi;
    /*int minlep = 1000000;
    int mini = 3;
    for (int i = 0; i < n; i++) {
        if (gyer[i] == true) {
            int ahol = fa[i][0];
            int lep = 0;
            while (ahol != fofa) {
                for (int j = 0; j < fa[ahol-1].size(); j++) {
                    if (gyer[fa[ahol-1][j]-1] != true) {
                        ahol = fa[ahol-1][j];
                    }
                }
                lep++;
            }
            if (lep < minlep) {
                minlep = lep;
                mini = i;
            }
        }
    }
    cout << mini+1;*/
}