using System; using System.Collections.Generic; using System.IO; using System.Linq; using static System.Math; using System.Text; using System.Threading; using System.Globalization; using System.Runtime.CompilerServices; using System.Runtime.InteropServices; using Library; namespace Program { public static class ProblemD { static bool SAIKI = false; static public int numberOfRandomCases = 0; static public void MakeTestCase(List _input, List _output, ref Func _outputChecker) { } static public void Solve() { var N = NN; var abC = Repeat(0, N * (N - 1) / 2).Select(_ => new { a = NN - 1, b = NN - 1, C = NN }).ToArray(); var cost = 0L; var uf = new LIB_UnionFind(N); foreach (var item in abC.OrderBy(e => e.C)) { if (uf.Unite(item.a, item.b)) { cost = item.C; } } Console.WriteLine(cost); } class Printer : StreamWriter { public override IFormatProvider FormatProvider { get { return CultureInfo.InvariantCulture; } } public Printer(Stream stream) : base(stream, new UTF8Encoding(false, true)) { base.AutoFlush = false; } public Printer(Stream stream, Encoding encoding) : base(stream, encoding) { base.AutoFlush = false; } } static LIB_FastIO fastio = new LIB_FastIODebug(); static public void Main(string[] args) { if (args.Length == 0) { fastio = new LIB_FastIO(); Console.SetOut(new Printer(Console.OpenStandardOutput())); } if (SAIKI) { var t = new Thread(Solve, 134217728); t.Start(); t.Join(); } else Solve(); Console.Out.Flush(); } static long NN => fastio.Long(); static double ND => fastio.Double(); static string NS => fastio.Scan(); static long[] NNList(long N) => Repeat(0, N).Select(_ => NN).ToArray(); static double[] NDList(long N) => Repeat(0, N).Select(_ => ND).ToArray(); static string[] NSList(long N) => Repeat(0, N).Select(_ => NS).ToArray(); static long Count(this IEnumerable x, Func pred) => Enumerable.Count(x, pred); static IEnumerable Repeat(T v, long n) => Enumerable.Repeat(v, (int)n); static IEnumerable Range(long s, long c) => Enumerable.Range((int)s, (int)c); static IOrderedEnumerable OrderByRand(this IEnumerable x) => Enumerable.OrderBy(x, _ => xorshift); static IOrderedEnumerable OrderBy(this IEnumerable x) => Enumerable.OrderBy(x.OrderByRand(), e => e); static IOrderedEnumerable OrderBy(this IEnumerable x, Func selector) => Enumerable.OrderBy(x.OrderByRand(), selector); static IOrderedEnumerable OrderByDescending(this IEnumerable x) => Enumerable.OrderByDescending(x.OrderByRand(), e => e); static IOrderedEnumerable OrderByDescending(this IEnumerable x, Func selector) => Enumerable.OrderByDescending(x.OrderByRand(), selector); static IOrderedEnumerable OrderBy(this IEnumerable x) => x.OrderByRand().OrderBy(e => e, StringComparer.OrdinalIgnoreCase); static IOrderedEnumerable OrderBy(this IEnumerable x, Func selector) => x.OrderByRand().OrderBy(selector, StringComparer.OrdinalIgnoreCase); static IOrderedEnumerable OrderByDescending(this IEnumerable x) => x.OrderByRand().OrderByDescending(e => e, StringComparer.OrdinalIgnoreCase); static IOrderedEnumerable OrderByDescending(this IEnumerable x, Func selector) => x.OrderByRand().OrderByDescending(selector, StringComparer.OrdinalIgnoreCase); static string Join(this IEnumerable x, string separator = "") => string.Join(separator, x); static uint xorshift { get { _xsi.MoveNext(); return _xsi.Current; } } static IEnumerator _xsi = _xsc(); static IEnumerator _xsc() { uint x = 123456789, y = 362436069, z = 521288629, w = (uint)(DateTime.Now.Ticks & 0xffffffff); while (true) { var t = x ^ (x << 11); x = y; y = z; z = w; w = (w ^ (w >> 19)) ^ (t ^ (t >> 8)); yield return w; } } static bool Chmax(this ref T lhs, T rhs) where T : struct, IComparable { if (lhs.CompareTo(rhs) < 0) { lhs = rhs; return true; } return false; } static bool Chmin(this ref T lhs, T rhs) where T : struct, IComparable { if (lhs.CompareTo(rhs) > 0) { lhs = rhs; return true; } return false; } static void Fill(this T[] array, T value) => array.AsSpan().Fill(value); static void Fill(this T[,] array, T value) => MemoryMarshal.CreateSpan(ref array[0, 0], array.Length).Fill(value); static void Fill(this T[,,] array, T value) => MemoryMarshal.CreateSpan(ref array[0, 0, 0], array.Length).Fill(value); static void Fill(this T[,,,] array, T value) => MemoryMarshal.CreateSpan(ref array[0, 0, 0, 0], array.Length).Fill(value); } } namespace Library { class LIB_UnionFind { int[] d; T[] v; Func f; [MethodImpl(MethodImplOptions.AggressiveInlining)] public LIB_UnionFind(IEnumerable s, Func func) { v = s.ToArray(); d = Enumerable.Repeat(-1, v.Length).ToArray(); f = func; } [MethodImpl(MethodImplOptions.AggressiveInlining)] public bool Unite(long x, long y) { x = Root(x); y = Root(y); if (x != y) { d[x] = d[x] + d[y]; v[x] = f(v[x], v[y]); d[y] = (int)x; } return x != y; } [MethodImpl(MethodImplOptions.AggressiveInlining)] public bool IsSame(long x, long y) => Root(x) == Root(y); [MethodImpl(MethodImplOptions.AggressiveInlining)] public long Root(long x) => d[x] < 0 ? x : d[x] = (int)Root(d[x]); [MethodImpl(MethodImplOptions.AggressiveInlining)] public long Count(long x) => -d[Root(x)]; [MethodImpl(MethodImplOptions.AggressiveInlining)] public T Calc(long x) => v[Root(x)]; } class LIB_UnionFind : LIB_UnionFind { [MethodImpl(MethodImplOptions.AggressiveInlining)] public LIB_UnionFind(long n) : base(Enumerable.Repeat(0, (int)n), (x, y) => x + y) { } [MethodImpl(MethodImplOptions.AggressiveInlining)] new private void Calc(long x) { } } class LIB_FastIO { [MethodImpl(MethodImplOptions.AggressiveInlining)] public LIB_FastIO() { str = Console.OpenStandardInput(); } readonly Stream str; readonly byte[] buf = new byte[2048]; int len, ptr; [MethodImpl(MethodImplOptions.AggressiveInlining)] byte read() { if (ptr >= len) { ptr = 0; if ((len = str.Read(buf, 0, 2048)) <= 0) { return 0; } } return buf[ptr++]; } [MethodImpl(MethodImplOptions.AggressiveInlining)] char Char() { byte b = 0; do b = read(); while (b < 33 || 126 < b); return (char)b; } [MethodImpl(MethodImplOptions.AggressiveInlining)] virtual public string Scan() { var sb = new StringBuilder(); for (var b = Char(); b >= 33 && b <= 126; b = (char)read()) sb.Append(b); return sb.ToString(); } [MethodImpl(MethodImplOptions.AggressiveInlining)] virtual public long Long() { long ret = 0; byte b = 0; var ng = false; do b = read(); while (b != '-' && (b < '0' || '9' < b)); if (b == '-') { ng = true; b = read(); } for (; true; b = read()) { if (b < '0' || '9' < b) return ng ? -ret : ret; else ret = (ret << 3) + (ret << 1) + b - '0'; } } [MethodImpl(MethodImplOptions.AggressiveInlining)] virtual public double Double() { return double.Parse(Scan(), CultureInfo.InvariantCulture); } } class LIB_FastIODebug : LIB_FastIO { Queue param = new Queue(); [MethodImpl(MethodImplOptions.AggressiveInlining)] string NextString() { if (param.Count == 0) foreach (var item in Console.ReadLine().Split(' ')) param.Enqueue(item); return param.Dequeue(); } [MethodImpl(MethodImplOptions.AggressiveInlining)] public LIB_FastIODebug() { } [MethodImpl(MethodImplOptions.AggressiveInlining)] public override string Scan() => NextString(); [MethodImpl(MethodImplOptions.AggressiveInlining)] public override long Long() => long.Parse(NextString()); [MethodImpl(MethodImplOptions.AggressiveInlining)] public override double Double() => double.Parse(NextString()); } }