#include <bits/stdc++.h>

using namespace std;

const int MAXN = 100005;

vector<int> graf[MAXN];
bool viz[MAXN];
int ans, start;
bool gata;

void dfs(int nod, int prec, int dir, int cnt){
    if(viz[nod] || gata) return;
    viz[nod] = 1;
    for(auto x:graf[nod]){
        if(x == prec) continue;
        dfs(x, nod, dir, cnt + 1);
    }
    if((int)graf[nod].size() == 1 && graf[nod][0] == prec){
        if(dir) ans = max(ans, cnt);
        else{
            start = nod;
            gata = 1;
        }
    }
}

int main()
{
    ifstream fin("darb.in");
    ofstream fout("darb.out");
    int n;
    fin >> n;
    for(int i = 1; i < n; ++i){
        int x, y;
        fin >> x >> y;
        graf[x].push_back(y);
        graf[y].push_back(x);
    }
    dfs(1, 0, 0, 1);
    gata = 0;
    memset(viz, 0, sizeof(viz));
    dfs(start, 0, 1, 1);
    fout << ans;
    return 0;
}