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

using namespace std;

int N;
vector < int > L[Nmax];
bitset <Nmax> used;
int dp[Nmax];
int Nodmaxim, maxim;

inline void Read()
{
    ifstream f("darb.in");
    f >> N;
    int i, x, y;
    for(i = 1; i < N; i++)
    {
        f >> x >> y;
        L[x].push_back(y);
        L[y].push_back(x);
    }
    f.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];
                Nodmaxim = it;
            }
            DFS(it);
        }
}

inline void Solve()
{
    DFS(1);
    for(int i = 1; i <= N; i++)
        dp[i] = used[i] = 0;
    DFS(Nodmaxim);
}

inline void Write()
{
    ofstream g("darb.out");
    g << maxim + 1 << "\n";
    g.close();
}

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