#include <bits/stdc++.h>

using namespace std;

int main()
{
    int n, i, a, b;
    cin >> n;
    int osv[n], ert[n];
    for(i=0; i<n; i++)
    {
        osv[i] = -1;
        ert[i] = 0;
    }
    vector<vector<int>> vec(n);
    queue<int>q;
    for(i=0; i<n-1; i++)
    {
        cin >> a >> b;
        a--, b--;
        osv[b] = a;
        vec[a].push_back(b);
    }
    for(i=0; i<n; i++)if(osv[i]==-1)break;
    q.push(i);
    while(!q.empty())
    {
        a = q.front();
        q.pop();
        for(auto i:vec[a])
        {
            ert[i]=1+ert[a];
            q.push(i);
        }
    }
    cout << max_element(ert, ert+n)-ert+1;
    return 0;
}