#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

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

vector<int> G[100002];
queue<int> Q;
int N;
int D[100002];
int Use[100002];
int Level[100002];
int M;
int NodMax;

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

        G[x].push_back(y);
        G[y].push_back(x);
    }
}
void BFS(int s)
{
    for(int i=1;i<=N;i++)
        D[i] = -1;
    D[s] = 0;
    Q.push(s);

    while(!Q.empty())
    {
        int nod = Q.front();
        Q.pop();

        for(int i=0;i<G[nod].size();i++)
        {
            int vecin = G[nod][i];
            if (D[vecin] == -1)
            {
                D[vecin] = D[nod] + 1;
                Q.push(vecin);
            }
        }
        if (M < D[nod])
            M = D[nod];
    }

}

void DFS(int nod)
{
    Use[nod] = 1;

    for(int i=0;i<G[nod].size();i++)
    {
        int vecin = G[nod][i];
        if (Use[vecin] == 0)
        {
            Level[vecin] = Level[nod] + 1;
            if (Level[vecin] > M)
            {
                M = Level[vecin];
                NodMax = vecin;
            }

            DFS(vecin);
        }
    }
}

int main()
{
    Read();

    DFS(1);
    for(int i=1;i<=N;i++)
    {
        Use[i] = Level[i] = 0;
        //BFS(i);
    }
    DFS(NodMax);
    fout<<M+1;
    return 0;
}