#include<fstream>
#include<cstring>
#include<vector>

using namespace std;

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

const int N = 100100;

int i, n, x, y, ma, best, t, viz[N];

vector<int> v[N];

void dfs(int x) {
    viz[x] = 1;
    t++;
    if (t > ma) {
        ma = t;
        best = x;
    }
    for (int i = 0; i < v[x].size(); ++i) {
        if (!viz[v[x][i]]) {
            dfs(v[x][i]);
        }
    }
    t--;
}

int main() {
    fin >> n;
    for (i = 1; i < n; ++i) {
        fin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    dfs(1);
    memset(viz, 0, sizeof(viz));
    dfs(best);
    fout << ma;
    return 0;
}