/*
 * Diametrul unui arbore
 */

#include    <iostream>
#include    <fstream>
#include    <vector>

using namespace std;

ifstream fin("darb.in");
ofstream fout("darb.out");

const int MAX_N = 100005;

int N, distmax;
vector < int > V[MAX_N];
bool beenThere[MAX_N];

void Read()
{
    fin >> N;
    for(int i = 1; i <= N - 1; i++)
    {
        int x, y;
        fin >> x >> y;
        V[x].push_back(y);
        V[y].push_back(x);
    }
}

void DFS(int node, int dist)
{
    if(dist > distmax)
        distmax = dist;

    beenThere[node] = true;
    for(unsigned int i = 0; i < V[node].size(); i++)
    {
        if(!beenThere[V[node][i]])
            DFS(V[node][i], dist + 1);
    }
    beenThere[node] = false;
}

void Solve()
{
    for(int i = 0; i < N; i++)
        DFS(i, 0);

    fout << distmax;
}

int main()
{
    Read();
    Solve();
    return 0;
}