#include <bits/stdc++.h>
using namespace std;
const long long inf = 2147383647;
const double pi = 2 * acos(0.0);
const double eps = 1e-9;
struct debugger {
  template <typename T>
  debugger &operator,(const T &v) {
    cerr << v << " ";
    return *this;
  }
} dbg;
inline long long gcd(long long a, long long b) {
  a = ((a) < 0 ? -(a) : (a));
  b = ((b) < 0 ? -(b) : (b));
  while (b) {
    a = a % b;
    swap(a, b);
  }
  return a;
}
long long ext_gcd(long long A, long long B, long long *X, long long *Y) {
  long long x2, y2, x1, y1, x, y, r2, r1, q, r;
  x2 = 1;
  y2 = 0;
  x1 = 0;
  y1 = 1;
  for (r2 = A, r1 = B; r1 != 0;
       r2 = r1, r1 = r, x2 = x1, y2 = y1, x1 = x, y1 = y) {
    q = r2 / r1;
    r = r2 % r1;
    x = x2 - (q * x1);
    y = y2 - (q * y1);
  }
  *X = x2;
  *Y = y2;
  return r2;
}
inline long long modInv(long long a, long long m) {
  long long x, y;
  ext_gcd(a, m, &x, &y);
  x %= m;
  if (x < 0) x += m;
  return x;
}
inline long long power(long long a, long long p) {
  long long res = 1, x = a;
  while (p) {
    if (p & 1) res = (res * x);
    x = (x * x);
    p >>= 1;
  }
  return res;
}
inline long long bigmod(long long a, long long p, long long m) {
  long long res = 1 % m, x = a % m;
  while (p) {
    if (p & 1) res = (res * x) % m;
    x = (x * x) % m;
    p >>= 1;
  }
  return res;
}
vector<int> adj[500010];
int vis[500010];
bool compare(const int &a, const int &b) {
  if (vis[a] < vis[b])
    return true;
  else
    return false;
}
int arr[500010];
int bfs(int s) {
  vis[1] = 1;
  vector<int> v;
  vis[s] = 0;
  queue<int> q;
  q.push(s);
  while (!q.empty()) {
    int s = q.front();
    q.pop();
    if (adj[s].size() == 1) {
      v.push_back(s);
      continue;
    }
    for (long long i = (0); i <= (((long long)(adj[s]).size()) - 1); ++i) {
      int t = adj[s][i];
      if (vis[t] == -1) {
        vis[t] = vis[s] + 1;
        q.push(t);
      }
    }
  }
  sort((v).begin(), (v).end(), compare);
  for (long long i = (0); i <= (((long long)(v).size()) - 1); ++i) {
    int s = v[i];
    arr[s] = vis[s];
    if (i)
      arr[s] =
          ((arr[s]) > (arr[v[i - 1]] + 1) ? (arr[s]) : (arr[v[i - 1]] + 1));
  }
  return arr[v[((long long)(v).size()) - 1]];
}
int main() {
  memset(vis, -1, sizeof(vis));
  int n;
  scanf("%d", &n);
  for (long long i = (0); i <= (n - 2); ++i) {
    int a, b;
    scanf("%d %d", &a, &b);
    adj[a].push_back(b);
    adj[b].push_back(a);
  }
  int res = 0;
  for (long long i = (0); i <= (((long long)(adj[1]).size()) - 1); ++i) {
    int s = adj[1][i];
    res = max(res, bfs(s) + 1);
  }
  printf("%d\n", res);
  return 0;
}
