using System;

using System.Collections.Generic;

using System.Linq;

​

namespace IsCyclic

{

    public class Graph

    {

        private int[][] childNodes;

        public Graph(int[][] nodes)

        {

            this.childNodes = nodes;

        }

​

        public int[][] ChildNodes

        {

            get

            {

                return this.childNodes;

            }

​

            set

            {

                this.childNodes = value;

            }

        }

​

        public bool IsCyclic()

        {

            Queue<int> nodes = new Queue<int>();

            bool[] visited = new bool[ChildNodes.GetLength(0)];

            nodes.Enqueue(0);

            while (nodes.Count > 0)

            {

                int currentNode = nodes.Dequeue();

                if (visited[currentNode] == true)

                {

                    return true;

                }

​

                visited[currentNode] = true;

                foreach (int childNode in this.childNodes[currentNode])

                {

                    nodes.Enqueue(childNode);

                }

            }

​

            return false;

        }

    }

​

    public class IsCyclic

    {

        public static Graph CreateGraph()

        {

            int vertexCount = int.Parse(Console.ReadLine());

            int[][] graphArray = new int[vertexCount][];

            for (int i = 0; i < vertexCount; i++)

            {

                string sucessors = Console.ReadLine();

                string[] currentVertexSucessors = sucessors.Split(new char[]{',', ' '}, StringSplitOptions.RemoveEmptyEntries);

                graphArray[i] = currentVertexSucessors.Select(item => int.Parse(item)).ToArray();

                Array.Sort(graphArray[i]);

                if (graphArray[i].Contains(i))

                {

                    throw new ApplicationException("A vertex cannot be it's own successor");

                }

            }

​

            Graph newGraph = new Graph(graphArray);

            return newGraph;

        }

​

        public static void Main(string[] args)

        {

            Graph myGraph = CreateGraph();

            Console.WriteLine(myGraph.IsCyclic());

        }

    }

}