#include <bits/stdc++.h>
using namespace std;

int parcurge(int i, vector <vector <int>> &edges, vector <bool> &vazut) {
    int maxim = 0;
    vazut[i] = 0;
    for (int j = 0; j < edges[i].size(); j++)
        if (vazut[edges[i][j]])
            maxim = max(maxim, parcurge(edges[i][j], edges, vazut));
    return maxim + 1;
}

int main() {
    freopen("darb.in", "r", stdin);
    freopen("darb.out", "w", stdout);
    int n, i, x, y;
    cin >> n;
    vector <vector <int>>  edges(n + 1);
    vector <bool> vazut(n + 1);

    for (i = 1; i < n; i++) {
        cin >> x >> y;
        edges[x].push_back(y);
        edges[y].push_back(x);
    }

    queue <int> parcurse;
    parcurse.push(1);
    int ultim = 1, act;
    while (!parcurse.empty()) {
        act = parcurse.front();
        for (i = 0; i < edges[act].size(); i++) {
            if (!vazut[edges[act][i]])
                parcurse.push(edges[act][i]);
            vazut[edges[act][i]] = 1;
        }
        ultim = act;
        parcurse.pop();
    }
    cout << parcurge(ultim, edges, vazut);
    return 0;
}