#include <fstream>
#include <vector>
#define DIM 100005

using namespace std;

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

vector <int> L[DIM];
int n, i, j, p, u, nod, o, v[DIM], c[DIM], l[DIM], k;

int bfs(int start) {
    v[start] = 1;
    c[1] = start;
    int p = 1, u = 1;
    while (p <= u) {
        int nod = c[p];
        for (i=0;i<L[nod].size();i++) {
            int vecin = L[nod][i];
            if (v[vecin] == 0) {
                c[++u] = vecin;
                v[vecin] = 1;
                l[vecin] = 1 + l[nod];
            }
        }
        p++;
    }
    o = l[c[u]];
    return c[u];
}


int main()
{
    fin >> n;
    for (int t=1; t<=n-1; t++){
        fin >> i >> j;
        L[i].push_back(j);
        L[j].push_back(i);
    }
    k = bfs(1);
    for (i=1; i<=n; i++){
        v[i] = 0;
        l[i] = 0;
    }
    bfs(k);
    fout << o + 1;
    return 0;
}