Graphs: first part

using System;
using System.Collections.Generic;
using System.Linq;

namespace Graphs {
    internal static class Program {
        public static void Main() {
            if (!int.TryParse(Console.ReadLine(), out var n)) return;

            var list = new List<GraphPoint>();
            for (var i = 0; i < n; i++) list.Add(new GraphPoint(i + 1));

            while (true) {
                var line = Console.ReadLine();
                if (string.IsNullOrEmpty(line)) break;

                var parts = line.Split(' ').Select(p => (int.TryParse(p, out var val), val))
                    .Where(p => p.Item1).Select(p => p.val).ToArray();

                if (parts.Length != 2) continue;

                var a = parts[0];
                var b = parts[1];

                list[a - 1].Neighbours.Add(list[b - 1]);
                list[b - 1].Neighbours.Add(list[a - 1]);
            }

            var chains = new List<List<GraphPoint>>();

            foreach (var t in list) {
                var neighboursList = new List<GraphPoint>();
                t.GetMeAndNeighbours(neighboursList);
                chains.Add(neighboursList.OrderBy(p => p.Value).ToList());
            }

            chains = chains.Distinct(new GraphPoint.EqualityComparer()).ToList();

            Console.WriteLine(chains.Count - 1);
        }

        public class GraphPoint {
            public int Value { get; }
            public List<GraphPoint> Neighbours { get; }

            public GraphPoint(int value) {
                Value = value;
                Neighbours = new List<GraphPoint>();
            }

            public void GetMeAndNeighbours(List<GraphPoint> points) {
                if (points.Contains(this)) return;
                points.Add(this);

                foreach (var point in Neighbours) point.GetMeAndNeighbours(points);
            }

            public override int GetHashCode() => Value.GetHashCode() ^ Neighbours.GetHashCode();

            public override string ToString() { return Value.ToString(); }

            public class EqualityComparer : IEqualityComparer<List<GraphPoint>> {
                public bool Equals(List<GraphPoint> x, List<GraphPoint> y) {
                    if (x == null && y == null) return true;
                    if (x == null || y == null || x.Count != y.Count) return false;

                    return !x.Where((t, i) => t.Value != y[i].Value).Any();
                }

                public int GetHashCode(List<GraphPoint> obj)
                    => obj.Aggregate(0, (current, point) => current ^ point.GetHashCode());
            }
        }
    }
}