#include <fstream>
#include <vector>
#include <cstring>

using namespace std;

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

const int NMax = 1e5;

vector <int> G[NMax + 5];

int N, NodM, Max, D[NMax + 5];

void Read()
{
    fin >> N;

    for(int i = 1, x, y; i < N; i++)
    {
        fin >> x >> y;

        G[x].push_back(y);
        G[y].push_back(x);
    }
}

void DFS(int Nod, int Tata)
{
    D[Nod] = D[Tata] + 1;

    if(D[Nod] > Max) Max = D[Nod], NodM = Nod;

    for(auto Vecin : G[Nod])
        if(Vecin != Tata)
            DFS(Vecin, Nod);
}

void Solve()
{
    DFS(1, 0);
    memset(D, 0, sizeof(D));
    DFS(NodM, 0);

    fout << Max << '\n';
}

int main()
{
    Read();
    Solve();

    fin.close();
    fout.close();

    return 0;
}