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

using namespace std;

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

int n, nivelMaxim, raspuns;
int nivele[100005];
vector<int> mat[100005];

void dfs(int nodSunt, int nodVin) {
    for (int i = 0; i < mat[nodSunt].size(); ++i) {
        if (mat[nodSunt][i] != nodVin) {
            nivele[mat[nodSunt][i]] = nivele[nodSunt] + 1;
            dfs(mat[nodSunt][i], nodSunt);
        }
    }

    if (mat[nodSunt].size() == 1) {
        if (nivelMaxim < nivele[nodSunt]) {
            nivelMaxim = nivele[nodSunt];
            raspuns = nodSunt;
        }
    }

}

int main() {
    fin >> n;

    for (int i = 1; i < n; ++i) {
        int x, y;
        fin >> x >> y;
        mat[x].push_back(y);
        mat[y].push_back(x);
    }

    nivelMaxim = -1;
    dfs(1, 0);

    for (int i = 1; i <= n; ++i) {
        nivele[i] = 0;
    }

    dfs(raspuns, 0);
    fout << nivelMaxim + 1;

    return 0;
}