#include <fstream>
#include <list>
#include <vector>
#include <queue>
#define file "darb"
#define N 100003

using namespace std;

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

int n,x,y,frz;

bool f[N];

vector<int> v[N];

int BFS(int nod)
{
    int h[N] = {0};
    queue<int> q;

    q.push(nod);
    h[nod] = 1;
    f[1] = 1;

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

        for(vector<int>::iterator it = v[nod].begin(); it != v[nod].end(); ++it)
            if(!f[*it])
            {
                q.push(*it);
                f[*it] = 1;
                h[*it] = h[nod] + 1;
            }
    }

    int Max = 0;
    for(int i=1; i<=n; ++i)
        if(Max < h[i])
        {
            Max = h[i];
            frz = i;
        }
    return Max;
}

int main()
{
    fin>>n;
    for(int i=1; i<n; ++i)
    {
        fin>>x>>y;

        v[x].push_back(y);
        v[y].push_back(x);

    }

    BFS(1);
    fout<<BFS(frz)<<"\n";

    fin.close(); fout.close();
    return 0;
}