#include <bits/stdc++.h>
using namespace std;
inline long long getint() {
  long long _x = 0, _tmp = 1;
  char _tc = getchar();
  while ((_tc < '0' || _tc > '9') && _tc != '-') _tc = getchar();
  if (_tc == '-') _tc = getchar(), _tmp = -1;
  while (_tc >= '0' && _tc <= '9') _x *= 10, _x += (_tc - '0'), _tc = getchar();
  return _x * _tmp;
}
long long mypow(long long _a, long long _x, long long _mod) {
  if (_x == 0) return 1ll;
  long long _tmp = mypow(_a, _x / 2, _mod);
  _tmp = (_tmp * _tmp) % _mod;
  if (_x & 1) _tmp = (_tmp * _a) % _mod;
  return _tmp;
}
inline long long add(long long _x, long long _y,
                     long long _mod = 1000000007ll) {
  long long _ = _x + _y;
  if (_ >= _mod) _ -= _mod;
  return _;
}
inline long long sub(long long _x, long long _y,
                     long long _mod = 1000000007ll) {
  long long _ = _x - _y;
  if (_ < 0) _ += _mod;
  return _;
}
inline long long mul(long long _x, long long _y,
                     long long _mod = 1000000007ll) {
  long long _ = _x * _y;
  if (_ >= _mod) _ %= _mod;
  return _;
}
inline bool equal(double _x, double _y) {
  return _x > _y - 1e-9 && _x < _y + 1e-9;
}
int __ = 1, _cs;
int n;
vector<int> v[555555];
void build() {}
void init() {
  n = getint();
  for (int i = 1; i < n; i++) {
    int xi = getint();
    int yi = getint();
    v[xi].push_back(yi);
    v[yi].push_back(xi);
  }
}
vector<int> dep;
void DFS(int now, int prt, int tdep) {
  if ((int)v[now].size() == 1) {
    dep.push_back(tdep);
    return;
  }
  for (size_t i = 0; i < v[now].size(); i++)
    if (v[now][i] != prt) DFS(v[now][i], now, tdep + 1);
}
long long cal(int tn) {
  dep.clear();
  DFS(tn, 1, 0);
  sort((dep).begin(), (dep).end());
  for (size_t i = 1; i < dep.size(); i++) dep[i] = max(dep[i], dep[i - 1] + 1);
  return dep.back();
}
void solve() {
  long long ans = 0;
  for (size_t i = 0; i < v[1].size(); i++) ans = max(ans, cal(v[1][i]));
  cout << ans + 1 << endl;
}
int main() {
  build();
  while (__--) {
    init();
    solve();
  }
}
