#include <iostream>
#include <fstream>
#include <map>
#include <queue>
#include <vector>
#include <string>
#include <cmath>
#include <cstring>
#include <set>
using namespace std;
ifstream f("darb.in");
ofstream g("darb.out");
///#define f cin
///#define g cout
#define NMAX 110000
int n, m, x, y;
vector<int> adj[NMAX];
int dist[NMAX];
int viz[NMAX];
int ultim;
int dmax;
queue<int> q;
void dfs(int nod, int d)
{
    dmax = max(dmax, d);
    if (viz[nod] == 1)
    {
        for (auto vecin : adj[nod])
        {
            viz[nod] = 0;
            dfs(vecin, d + 1);
        }
    }
}
void bfs()
{
    while (!q.empty())
    {
        int curent = q.front();
        q.pop();
        ultim = curent;
        viz[curent] = 1;
        for (auto vecin : adj[curent])
        {
            if (!viz[vecin])
            {
                viz[vecin] = 1;
                dist[vecin] = dist[curent] + 1;
                q.push(vecin);
            }
        }
    }
}
int main()
{
    f >> n;
    for (int i = 1; i <= n - 1; i++)
    {
        int x, y;
        f >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }
    q.push(1);
    bfs();
    dfs(ultim, 0);
    g << dmax;
    return 0;
}