#include <bits/stdc++.h>

using namespace std;

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

unsigned int N;
unsigned int a, b;

bool seen[100001];
vector <int> v[100001];
queue <int> Q;
int sol[100001];
int node, i;

int main()
{
    fin >> N;
    for (i=1; i<=N-1; i++)
    {
        fin >> a >> b;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    sol[1] = 1;
    seen[1] = 1;
    Q.push(1);
    while (!Q.empty())
    {
        node = Q.front();
        Q.pop();
        seen[node] = 1;
        for (i=0; i<v[node].size(); i++)
            if (seen[v[node][i]] == 0)
            {
                seen[v[node][i]] = 1;
                sol[v[node][i]] = sol[node] + 1;
                Q.push(v[node][i]);
            }
    }
    sol[node] = 1;
    seen[node] = 0;
    Q.push(node);
    while (!Q.empty())
    {
        node = Q.front();
        Q.pop();
        seen[node] = 0;
        for (i=0; i<v[node].size(); i++)
            if (seen[v[node][i]] == 1)
            {
                seen[v[node][i]] = 0;
                sol[v[node][i]] = sol[node] + 1;
                Q.push(v[node][i]);
            }
    }
    fout << sol[node];
    return 0;
}