// Optimise
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;

// #define MULTI_TEST
#ifdef LOCAL
#define db(...) ZZ(#__VA_ARGS__, __VA_ARGS__);
#define pc(...) PC(#__VA_ARGS__, __VA_ARGS__);
template <typename T, typename U>
ostream &operator<<(ostream &out, const pair<T, U> &p)
{
    out << '[' << p.first << ", " << p.second << ']';
    return out;
}
template <typename Arg>
void PC(const char *name, Arg &&arg)
{
    while (*name == ',' || *name == ' ')
        name++;
    std::cerr << name << " { ";
    for (const auto &v : arg)
        cerr << v << ' ';
    cerr << " }\n";
}
template <typename Arg1, typename... Args>
void PC(const char *names, Arg1 &&arg1, Args &&... args)
{
    while (*names == ',' || *names == ' ')
        names++;
    const char *comma = strchr(names, ',');
    std::cerr.write(names, comma - names) << " { ";
    for (const auto &v : arg1)
        cerr << v << ' ';
    cerr << " }\n";
    PC(comma, args...);
}
template <typename Arg1>
void ZZ(const char *name, Arg1 &&arg1)
{
    std::cerr << name << " = " << arg1 << endl;
}
template <typename Arg1, typename... Args>
void ZZ(const char *names, Arg1 &&arg1, Args &&... args)
{
    const char *comma = strchr(names + 1, ',');
    std::cerr.write(names, comma - names) << " = " << arg1;
    ZZ(comma, args...);
}
#else
#define db(...)
#define pc(...)
#endif

using ll = long long;
template <typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define f first
#define s second
#define pb push_back
#define all(v) v.begin(), v.end()
auto TimeStart = chrono::steady_clock::now();
auto seed = TimeStart.time_since_epoch().count();
std::mt19937 rng(seed);
template <typename T>
using Random = std::uniform_int_distribution<T>;

const int NAX = 2e5 + 5, MOD = 1000000007;
vector<int> adj[NAX];
int dp[NAX][20];
int ans = 0;

void dfs(int node, int par)
{
    for (auto child : adj[node])
        if (child != par)
        {
            dfs(child, node);
            for (int i = 0; i < 20; ++i)
                dp[node][i] += dp[child][i];
        }
    int st = 0;
    for (int i = 19; i >= 0; --i)
        if (dp[node][i] >= 2)
        {
            st = i;
            break;
        }
    for (int i = st;; ++i)
        if (dp[node][i] == 0)
        {
            dp[node][i] = 1;
            ans = max(ans, i);
            for (int j = i - 1; j >= 0; --j)
                dp[node][j] = 0;
            return;
        }
}

void solveCase(int caseNo)
{
    int n, u, v;
    cin >> n;
    for (int i = 1; i < n; ++i)
    {
        cin >> u >> v;
        adj[u].pb(v);
        adj[v].pb(u);
    }
    dfs(1, 0);
    cout << ans << '\n';
#ifdef LOCAL
    for (int i = 1; i <= n; ++i)
    {
        cout << i << '\n';
        for (int j = 0; j < 20; ++j)
            cout << dp[i][j] << ' ';
        cout << '\n';
    }
#endif
}

int main()
{
#ifndef LOCAL
    ios_base::sync_with_stdio(0);
    cin.tie(0);
#endif
    int t = 1;
#ifdef MULTI_TEST
    cin >> t;
#endif
    for (int i = 1; i <= t; ++i)
    {
        solveCase(i);
#ifdef TIME
        cerr << "Case #" << i << ": Time " << chrono::duration<double>(chrono::steady_clock::now() - TimeStart).count() << " s.\n";
        TimeStart = chrono::steady_clock::now();
#endif
    }
    return 0;
}


Measured memory_bytes: 23296