#nullable enable using System.Numerics; void Run() { var v = new HashSet<int>(); var e = new HashSet<(int, int)>(); var f = new HashSet<(int, int, int)>(); var q = Int(); for (var i = 0; i < q; i++) { var a = Int(); var b = Int(); var c = Int(); v.Add(a); v.Add(b); v.Add(c); e.Add((a, b)); e.Add((a, c)); e.Add((b, c)); f.Add((a, b, c)); } var ans = v.Count - e.Count + f.Count; Out(ans); } #region AtCoderIO _io_; var _backend_ = new StandardIOBackend(); _io_ = new(){ Backend = _backend_ }; Run(); _backend_.Flush(); string String() => _io_.Next(); int Int() => int.Parse(String()); void Out(object? x, string? sep = null) => _io_.Out(x, sep); class AtCoderIO { public required StandardIOBackend Backend { get; init; } Memory<string> _input = Array.Empty<string>(); int _iter = 0; public string Next() { while (_iter >= _input.Length) (_input, _iter) = (Backend.ReadLine().Trim().Split(' '), 0); return _input.Span[_iter++]; } public void Out(object? x, string? separator = null) { if (x == null) return; separator ??= Environment.NewLine; if (x is System.Collections.IEnumerable a and not string) { var objects = a.Cast<object>(); if (separator == Environment.NewLine && !objects.Any()) return; x = string.Join(separator, objects); } Backend.WriteLine(x); } } class StandardIOBackend { readonly StreamReader _sr = new(Console.OpenStandardInput()); readonly StreamWriter _sw = new(Console.OpenStandardOutput()) { AutoFlush = false }; public string ReadLine() => _sr.ReadLine()!; public void WriteLine(object? value) => _sw.WriteLine(value); public void Flush() => _sw.Flush(); } #endregion static class Extensions { public static T[] Repeat<T>(this int time, Func<T> F) => Enumerable.Range(0, time).Select(_ => F()).ToArray(); }