#include <bits/stdc++.h>
using namespace std;
string np = "darb";
ifstream f(np + ".in");
ofstream g(np + ".out");

// #define f cin
// #define g cout

int n, t, d[100003] = {0, 1}, k = 1, rez = 1;
vector<int> adj[100003];

void dfs1(int nod)
{
    for (auto next : adj[nod])
        if (!d[next])
        {
            d[next] = d[nod] + 1;
            if (d[next] > d[k])
                k = next;
            dfs1(next);
        }
}
void dfs2(int nod)
{
    for (auto next : adj[nod])
        if (!d[next])
            d[next] = d[nod] + 1, rez = max(rez, d[next]),
            dfs2(next);
}
int main()
{
    f >> n;
    for (int x, y, i = 1; i < n; i++)
        f >> x >> y, adj[x].emplace_back(y), adj[y].emplace_back(x);

    dfs1(1);
    memset(d, 0, sizeof d);
    d[k] = 1;
    dfs2(k);

    g << rez;

    return 0;
}