#include <iostream>
#include <fstream>
#include <queue>
#include <vector>
using namespace std;
ifstream fin("darb.in");
ofstream fout("darb.out");

vector < int > muchii[100001];
queue < int > coada;
bool vizitat[100001];
int distanta[100001];
int ultim_nod;

void BFS() {
    int nod, vecin;
    while(coada.size() > 0) {
        nod = coada.front();
        coada.pop();
        for (int i = 0; i < muchii[nod].size(); ++i) {
            vecin = muchii[nod][i];
            if (distanta[vecin] == -1) {
                coada.push(vecin);
                distanta[vecin] = distanta[nod] + 1;
            }
        }
    }
}
int lungime = 0, maxim = 0;
void DFS(int nod) {
    vizitat[nod] = 1;
    for (int i = 0; i < muchii[nod].size(); ++i) {
        int vecin = muchii[nod][i];
        if(vizitat[vecin] == 0) {
            ++lungime;
            DFS(vecin);
            if (lungime > maxim) {
                maxim = lungime;
            }
            --lungime;
        }
    }
}

int main()
{
    int n;
    fin >> n;
    for (int i = 1; i < n; ++i) {
        int x, y;
        fin >> x >> y;
        muchii[x].push_back(y);
        muchii[y].push_back(x);
    }
    for (int i = 1; i <= n; ++i) {
        distanta[i] = -1;
    }
    distanta[1] = 0;
    coada.push(1);
    BFS();
    int prim_nod = 0, mx = 0;
    for (int i = 1; i <= n; ++i) {
        if (distanta[i] > mx) {
            mx = distanta[i];
            prim_nod = i;
        }
    }
    DFS(prim_nod);
    fout << maxim + 1;



    return 0;
}