#include <iostream>
#include<fstream>
#include<vector>
using namespace std;
ifstream f("darb.in");
ofstream g("darb.out");
vector<vector<int> >a;
bool viz[100001];
int N, lg, lgmax, nod;
void dfs(int X, int lg)
{
    if(lg > lgmax)
    {
        lgmax = lg;
        nod = X;
    }
    viz[X] = 1;
    for(unsigned int i = 0; i < a[X].size(); i++)
    {
        int nod = a[X][i];
        if(!viz[nod])
        {
            dfs(nod, lg + 1);
        }
    }
}
int main()
{
    int x, y;
    f >> N;
    a.resize(N + 1);
    for(int i = 1; i <= N - 1; i++)
    {
        f >> x >> y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    dfs(1, 0);
    for(int i = 1; i <= N; i++)
        viz[i] = 0;
    dfs(nod, 0);
    g << lgmax + 1;
    return 0;
}