#include <bits/stdc++.h>
#define Nmax 100005

using namespace std;

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

int N, dp[Nmax], maxim, poz;
vector <int> L[Nmax];
bool used[Nmax];

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

inline void DFS(int nod)
{
    used[nod] = 1;
    for(auto it : L[nod]) {
        if(!used[it]) {
            dp[it] = dp[nod] +  1;
            if(dp[it] > maxim) {
                maxim = dp[it];
                poz = it;
            }
            DFS(it);
        }
    }
}

inline void Solve()
{
    int i;
    DFS(1);
    for(i = 1; i <= N; i++) {
        dp[i] = 0;
        used[i] = 0;
    }
    DFS(poz);
    fout << maxim + 1 << "\n";
}

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